I've put my name forward as a Python mentor for the Google Summer of Code. That's not to say that the Python Software Foundation has accepted me as a mentor for official projects, but I'm making it known that I'm interested in helping out.
If you are thinking of applying and you have an interest that might overlap with mine, please feel free to email me.
Besides the specifics of a project, I believe I can help a lot with more general questions of software craftsmanship in an open source context.
In light of my previous blog entry, this definitely feels like an opportunity for me to "give back", although that phrase generally makes me cringe :-)
UPDATE (2005-06-30): I'm official mentoring Elliot Cohen's Bayesian Network project. Watch this blog for updates.