Yesterday I released two new releases of PyGObject and PyGTK. The most important change in both of releases is the support of a new API, available only in the svn version of Python which will prevent gobject and gtk from waking up once every 100 ms.
I would like to thank Guido van Rossum, Adam Olsen and Gustavo Carneiro for making sure that Python has enough support for this to be possible.
Unfortunately, it will take some time before this is widely used because it will only be included in Python 2.6. However, for OLPC the best option is probably to apply the patch from python issue 1583. Perhaps Linux distributors could do the same?