Added trampoline docs, made a note about internal APIs (and learned a bit about sphinx at the same time).

doc/common.txt

@@ -0,0 +1,4 @@
+.. |internal| replace::
+
+        This is considered an internal API, and it might change 
+        unexpectedly without being deprecated first.

doc/hubs.rst

@@ -35,10 +35,6 @@ If the selected hub is not idea for the application, another can be selected.
     Supplying None as the argument to :func:`eventlet.hubs.use_hub` causes it to select the default hub.
 
 
-
-.. autofunction:: eventlet.hubs.get_hub
-.. autofunction:: eventlet.hubs.get_default_hub
-
 How the Hubs Work
 -----------------
 
@@ -46,3 +42,11 @@ The hub has a main greenlet, MAINLOOP.  When one of the running coroutines needs
 to do some I/O, it registers a listener with the hub (so that the hub knows when to wake it up again), and then switches to MAINLOOP (via ``get_hub().switch()``).  If there are other coroutines that are ready to run, MAINLOOP switches to them, and when they complete or need to do more I/O, they switch back to the MAINLOOP.  In this manner, MAINLOOP ensures that every coroutine gets scheduled when it has some work to do.
 
 MAINLOOP is launched only when the first I/O operation happens, and it is not the same greenlet that __main__ is running in.  This lazy launching is why it's not necessary to explicitly call a dispatch() method like other frameworks, which in turn means that code can start using Eventlet without needing to be substantially restructured.
+
+More Hub-Related Functions
+---------------------------
+
+.. autofunction:: eventlet.hubs.get_hub
+.. autofunction:: eventlet.hubs.get_default_hub
+.. autofunction:: eventlet.hubs.trampoline
+

eventlet/hubs/__init__.py

@@ -15,8 +15,11 @@ def get_default_hub():
     * poll
     * select
     
-    It won't ever automatically select the pyevent hub, because it's not 
+    It won't automatically select the pyevent hub, because it's not 
     python-thread-safe.
+    
+    .. include:: ../../doc/common.txt
+    .. note :: |internal|
     """    
     
     # pyevent hub disabled for now because it is not thread-safe
@@ -67,6 +70,8 @@ def use_hub(mod=None):
 
 def get_hub():
     """Get the current event hub singleton object.
+    
+    .. note :: |internal|
     """
     try:
         hub = _threadlocal.hub
@@ -95,6 +100,8 @@ def trampoline(fd, read=None, write=None, timeout=None,
     If the specified *timeout* elapses before the socket is ready to read or
     write, *timeout_exc* will be raised instead of ``trampoline()``
     returning normally.
+    
+    .. note :: |internal|
     """
     t = None
     hub = get_hub()