http://docs.python.org/whatsnew/node18.html says that
unicode host names are allowed in the socket module
(automatically converting them by the IDNA spec), but
is seems the support is not fully implemented.

only the connect method of a socket instance will do
the auto conversion to a 'idna' string. 
socket.getaddr* functions will not!

Also other modules should support unicode hostnames.
(httplib already does) but urllib and urllib2 don't.