I've come to the conclusion that, as written, the higher level line-
oriented protocols which use the socket library (httplib, ftplib,
xmlrpclib, etc) won't work with socket timeouts.  They generally do
something like:

    self.file = self.sock.makefile('rb')

then use file methods to send and receive data on the socket.

Alas, the socket docs state:

Timeout mode internally sets the socket in non-blocking mode.
The blocking and timeout modes are shared between file descriptors
and socket objects that refer to the same network endpoint.  A
consequence of this is that file objects returned by the makefile()
method should only be used when the socket is in blocking mode; in
timeout or non-blocking mode file operations that cannot be
completed immediately will fail.  

I view this state of affairs as a bug which should be fixed at some
point, as these higher level protocol modules are probably the 
predominant way sockets get used in Python programs.