diff --git a/NEWS b/NEWS
index 71df493..8b14602 100644
--- a/NEWS
+++ b/NEWS
@@ -5,7 +5,6 @@
 * patcher.monkey_patch() method replacing util.wrap_*
 * monkeypatch threading support
 * removed api.named
-* move api_tests into greenthread_tests and hub_tests, or wherever's appropriate
 * imported timeout module from gevent, replace exc_after and with_timeout()
 * replace call_after with spawn_after; this is so that users don't see the Timer class
 * added cancel() method to GreenThread to support the semantic of "abort if not already in the middle of something"
diff --git a/benchmarks/context.py b/benchmarks/context.py
new file mode 100644
index 0000000..c237528
--- /dev/null
+++ b/benchmarks/context.py
@@ -0,0 +1,92 @@
+"""Test context switching performance of threading and eventlet"""
+
+import threading
+import time
+
+import eventlet
+from eventlet import hubs
+from eventlet.hubs import pyevent, epolls, poll, selects
+
+
+CONTEXT_SWITCHES = 100000
+
+def run(event, wait_event):
+    counter = 0
+    while counter <= CONTEXT_SWITCHES:
+        wait_event.wait()
+        wait_event.reset()
+        counter += 1
+        event.send()
+
+def test_eventlet():
+    event1 = eventlet.event.Event()
+    event2 = eventlet.event.Event()
+    event1.send()
+    thread1 = eventlet.spawn(run, event1, event2)
+    thread2 = eventlet.spawn(run, event2, event1)
+
+    thread1.wait()
+    thread2.wait()
+
+class BenchThread(threading.Thread):
+    def __init__(self, event, wait_event):
+        threading.Thread.__init__(self)
+        self.counter = 0
+        self.event = event
+        self.wait_event = wait_event
+
+    def run(self):
+        while self.counter <= CONTEXT_SWITCHES:
+            self.wait_event.wait()
+            self.wait_event.clear()
+            self.counter += 1
+            self.event.set()
+
+def test_thread():
+
+    event1 = threading.Event()
+    event2 = threading.Event()
+    event1.set()
+    thread1 = BenchThread(event1, event2)
+    thread2 = BenchThread(event2, event1)
+    thread1.start()
+    thread2.start()
+    thread1.join()
+    thread2.join()
+
+print "Testing with %d context switches" % CONTEXT_SWITCHES
+start = time.time()
+test_thread()
+print "threading: %.02f seconds" % (time.time() - start)
+
+try:
+    hubs.use_hub(pyevent)
+    start = time.time()
+    test_eventlet()
+    print "pyevent:   %.02f seconds" % (time.time() - start)
+except:
+    print "pyevent hub unavailable"
+
+try:
+    hubs.use_hub(epolls)
+    start = time.time()
+    test_eventlet()
+    print "epoll:     %.02f seconds" % (time.time() - start)
+except:
+    print "epoll hub unavailable"
+
+try:
+    hubs.use_hub(poll)
+    start = time.time()
+    test_eventlet()
+    print "poll:      %.02f seconds" % (time.time() - start)
+except:
+    print "poll hub unavailable"
+
+try:
+    hubs.use_hub(selects)
+    start = time.time()
+    test_eventlet()
+    print "select:    %.02f seconds" % (time.time() - start)
+except:
+    print "select hub unavailable"
diff --git a/eventlet/greenio.py b/eventlet/greenio.py
index b95ab39..1d305ea 100644
--- a/eventlet/greenio.py
+++ b/eventlet/greenio.py
@@ -1,3 +1,4 @@
+import eventlet
 from eventlet.hubs import trampoline
 from eventlet.hubs import get_hub
 
@@ -151,7 +152,7 @@ class GreenSocket(object):
                 set_nonblocking(client)
                 return type(self)(client), addr
             trampoline(fd, read=True, timeout=self.gettimeout(),
-                           timeout_exc=socket.timeout)
+                           timeout_exc=socket.timeout("timed out"))
 
     def bind(self, *args, **kw):
         fn = self.bind = self.fd.bind
@@ -170,15 +171,17 @@ class GreenSocket(object):
         fd = self.fd
         if self.gettimeout() is None:
             while not socket_connect(fd, address):
-                trampoline(fd, write=True, timeout_exc=socket.timeout)
+                trampoline(fd, write=True,
+                    timeout_exc=socket.timeout("timed out"))
         else:
             end = time.time() + self.gettimeout()
             while True:
                 if socket_connect(fd, address):
                     return
                 if time.time() >= end:
-                    raise socket.timeout
-                trampoline(fd, write=True, timeout=end-time.time(), timeout_exc=socket.timeout)
+                    raise socket.timeout("timed out")
+                trampoline(fd, write=True, timeout=end-time.time(),
+                        timeout_exc=socket.timeout("timed out"))
 
     def connect_ex(self, address):
         if self.act_non_blocking:
@@ -187,7 +190,8 @@ class GreenSocket(object):
         if self.gettimeout() is None:
             while not socket_connect(fd, address):
                 try:
-                    trampoline(fd, write=True, timeout_exc=socket.timeout)
+                    trampoline(fd, write=True,
+                                timeout_exc=socket.timeout(errno.EAGAIN))
                 except socket.error, ex:
                     return ex[0]
         else:
@@ -196,9 +200,10 @@ class GreenSocket(object):
                 if socket_connect(fd, address):
                     return 0
                 if time.time() >= end:
-                    raise socket.timeout
+                    raise socket.timeout(errno.EAGAIN)
                 try:
-                    trampoline(fd, write=True, timeout=end-time.time(), timeout_exc=socket.timeout)
+                    trampoline(fd, write=True, timeout=end-time.time(),
+                            timeout_exc=socket.timeout(errno.EAGAIN))
                 except socket.error, ex:
                     return ex[0]
 
@@ -254,21 +259,24 @@ class GreenSocket(object):
             trampoline(fd, 
                 read=True, 
                 timeout=self.timeout, 
-                timeout_exc=socket.timeout)
+                timeout_exc=socket.timeout("timed out"))
 
     def recvfrom(self, *args):
         if not self.act_non_blocking:
-            trampoline(self.fd, read=True, timeout=self.gettimeout(), timeout_exc=socket.timeout)
+            trampoline(self.fd, read=True, timeout=self.gettimeout(),
+                    timeout_exc=socket.timeout("timed out"))
         return self.fd.recvfrom(*args)
 
     def recvfrom_into(self, *args):
         if not self.act_non_blocking:
-            trampoline(self.fd, read=True, timeout=self.gettimeout(), timeout_exc=socket.timeout)
+            trampoline(self.fd, read=True, timeout=self.gettimeout(),
+                    timeout_exc=socket.timeout("timed out"))
         return self.fd.recvfrom_into(*args)
 
     def recv_into(self, *args):
         if not self.act_non_blocking:
-            trampoline(self.fd, read=True, timeout=self.gettimeout(), timeout_exc=socket.timeout)
+            trampoline(self.fd, read=True, timeout=self.gettimeout(),
+                    timeout_exc=socket.timeout("timed out"))
         return self.fd.recv_into(*args)
 
     def send(self, data, flags=0):
@@ -276,6 +284,8 @@ class GreenSocket(object):
         if self.act_non_blocking:
             return fd.send(data, flags)
         try:
+            trampoline(self.fd, write=True, timeout=self.gettimeout(),
+                    timeout_exc=socket.timeout("timed out"))
             return fd.send(data, flags)
         except socket.error, e:
             if e[0] in SOCKET_BLOCKING:
@@ -290,11 +300,11 @@ class GreenSocket(object):
             trampoline(fd, 
                 write=True, 
                 timeout=self.timeout, 
-                timeout_exc=socket.timeout)
+                timeout_exc=socket.timeout("timed out"))
             tail += self.send(data[tail:], flags)
 
     def sendto(self, *args):
-        trampoline(self.fd, write=True, timeout_exc=socket.timeout)
+        trampoline(self.fd, write=True, timeout_exc=socket.timeout("timed out"))
         return self.fd.sendto(*args)
 
     def setblocking(self, flag):
diff --git a/tests/debug_test.py b/tests/debug_test.py
index 40af038..25a11ef 100644
--- a/tests/debug_test.py
+++ b/tests/debug_test.py
@@ -118,11 +118,15 @@ class TestDebug(LimitedTestCase):
             eventlet.sleep(0)
             client.send(' ')
             eventlet.sleep(0)
+            # allow the "hurl" greenlet to trigger the KeyError
+            # not sure why the extra context switch is needed
+            eventlet.sleep(0)
         finally:
             sys.stderr = orig
             self.assertRaises(KeyError, gt.wait)
             debug.hub_exceptions(False)
-        self.assert_('Traceback' in fake.getvalue(), 
+        # look for the KeyError exception in the traceback
+        self.assert_('KeyError: 1' in fake.getvalue(), 
             "Traceback not in:\n" + fake.getvalue())
         
 if __name__ == "__main__":
diff --git a/tests/greenio_test.py b/tests/greenio_test.py
index 2cbaad4..0aa8823 100644
--- a/tests/greenio_test.py
+++ b/tests/greenio_test.py
@@ -8,6 +8,7 @@ import errno
 import eventlet
 import os
 import sys
+import array
 
 def bufsized(sock, size=1):
     """ Resize both send and receive buffers on a socket.
@@ -32,12 +33,190 @@ class TestGreenIo(LimitedTestCase):
         s.settimeout(0.1)
         gs = greenio.GreenSocket(s)
         try:
-            self.assertRaises(socket.timeout, gs.connect, ('192.0.2.1', 80))
+            gs.connect(('192.0.2.1', 80))
+            self.fail("socket.timeout not raised")
+        except socket.timeout, e:
+            self.assert_(hasattr(e, 'args'))
+            self.assertEqual(e.args[0], 'timed out')
         except socket.error, e:
             # unreachable is also a valid outcome
             if e[0] != errno.EHOSTUNREACH:
                 raise
 
+    def test_accept_timeout(self):
+        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        s.bind(('', 0))
+        s.listen(50)
+
+        s.settimeout(0.1)
+        gs = greenio.GreenSocket(s)
+        try:
+            gs.accept()
+            self.fail("socket.timeout not raised")
+        except socket.timeout, e:
+            self.assert_(hasattr(e, 'args'))
+            self.assertEqual(e.args[0], 'timed out')
+
+    def test_connect_ex_timeout(self):
+        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        s.settimeout(0.1)
+        gs = greenio.GreenSocket(s)
+        e = gs.connect_ex(('192.0.2.1', 80))
+        self.assertEquals(e, errno.EAGAIN)
+
+    def test_recv_timeout(self):
+        listener = greenio.GreenSocket(socket.socket())
+        listener.bind(('', 0))
+        listener.listen(50)
+
+        def server():
+            # accept the connection in another greenlet
+            sock, addr = listener.accept()
+
+            eventlet.sleep(.2)
+
+        gt = eventlet.spawn(server)
+
+        addr = listener.getsockname()
+
+        client = greenio.GreenSocket(socket.socket())
+        client.settimeout(0.1)
+
+        client.connect(addr)
+
+        try:
+            r = client.recv(8192)
+            self.fail("socket.timeout not raised")
+        except socket.timeout, e:
+            self.assert_(hasattr(e, 'args'))
+            self.assertEqual(e.args[0], 'timed out')
+
+        gt.wait()
+
+    def test_recvfrom_timeout(self):
+        gs = greenio.GreenSocket(
+            socket.socket(socket.AF_INET, socket.SOCK_DGRAM))
+        gs.settimeout(.1)
+        gs.bind(('', 0))
+
+        try:
+            gs.recvfrom(8192)
+            self.fail("socket.timeout not raised")
+        except socket.timeout, e:
+            self.assert_(hasattr(e, 'args'))
+            self.assertEqual(e.args[0], 'timed out')
+
+    def test_recvfrom_into_timeout(self):
+        buf = buffer(array.array('B'))
+
+        gs = greenio.GreenSocket(
+            socket.socket(socket.AF_INET, socket.SOCK_DGRAM))
+        gs.settimeout(.1)
+        gs.bind(('', 0))
+
+        try:
+            gs.recvfrom_into(buf)
+            self.fail("socket.timeout not raised")
+        except socket.timeout, e:
+            self.assert_(hasattr(e, 'args'))
+            self.assertEqual(e.args[0], 'timed out')
+
+    def test_recv_into_timeout(self):
+        buf = buffer(array.array('B'))
+
+        listener = greenio.GreenSocket(socket.socket())
+        listener.bind(('', 0))
+        listener.listen(50)
+
+        def server():
+            # accept the connection in another greenlet
+            sock, addr = listener.accept()
+
+            eventlet.sleep(.2)
+
+        gt = eventlet.spawn(server)
+
+        addr = listener.getsockname()
+
+        client = greenio.GreenSocket(socket.socket())
+        client.settimeout(0.1)
+
+        client.connect(addr)
+
+        try:
+            r = client.recv_into(buf)
+            self.fail("socket.timeout not raised")
+        except socket.timeout, e:
+            self.assert_(hasattr(e, 'args'))
+            self.assertEqual(e.args[0], 'timed out')
+
+        gt.wait()
+
+    def test_send_timeout(self):
+        listener = greenio.GreenSocket(socket.socket())
+        listener.bind(('', 0))
+        listener.listen(50)
+
+        def server():
+            # accept the connection in another greenlet
+            sock, addr = listener.accept()
+
+            eventlet.sleep(.5)
+
+        gt = eventlet.spawn(server)
+
+        addr = listener.getsockname()
+
+        client = greenio.GreenSocket(socket.socket())
+        client.settimeout(0.1)
+
+        client.connect(addr)
+
+        try:
+            msg = "A"*(8*1024*1024)
+
+            # want to exceed the size of the OS buffer so it'll block
+            for x in range(10):
+                client.send(msg)
+            self.fail("socket.timeout not raised")
+        except socket.timeout, e:
+            self.assert_(hasattr(e, 'args'))
+            self.assertEqual(e.args[0], 'timed out')
+
+        gt.wait()
+
+    def test_sendall_timeout(self):
+        listener = greenio.GreenSocket(socket.socket())
+        listener.bind(('', 0))
+        listener.listen(50)
+
+        def server():
+            # accept the connection in another greenlet
+            sock, addr = listener.accept()
+
+            eventlet.sleep(.5)
+
+        gt = eventlet.spawn(server)
+
+        addr = listener.getsockname()
+
+        client = greenio.GreenSocket(socket.socket())
+        client.settimeout(0.1)
+
+        client.connect(addr)
+
+        try:
+            msg = "A"*(8*1024*1024)
+
+            # want to exceed the size of the OS buffer so it'll block
+            client.sendall(msg)
+            self.fail("socket.timeout not raised")
+        except socket.timeout, e:
+            self.assert_(hasattr(e, 'args'))
+            self.assertEqual(e.args[0], 'timed out')
+
+        gt.wait()
+
     def test_close_with_makefile(self):
         def accept_close_early(listener):
             # verify that the makefile and the socket are truly independent
diff --git a/tests/test__greenness.py b/tests/test__greenness.py
index 714bc62..c737b0b 100644
--- a/tests/test__greenness.py
+++ b/tests/test__greenness.py
@@ -14,8 +14,10 @@ def start_http_server():
     #print "Serving HTTP on", sa[0], "port", sa[1], "..."
     httpd.request_count = 0
     def serve():
-        httpd.handle_request()
+        # increment the request_count before handling the request because
+        # the send() for the response blocks (or at least appeared to be)
         httpd.request_count += 1
+        httpd.handle_request()
     return spawn(serve), httpd, sa[1]
 
 class TestGreenness(unittest.TestCase):