I've been using <a href="http://psionides.github.com/Gitifier/" rel="nofollow">http://psionides.github.com/Gitifier/</a> (which can keep an eye on any git repo not just github) but I might have to give this a try.
Somewhat related, is it worth trying to build something that pushes to growl remotely? Seems like world of port blocking issues but maybe their is something out there that makes it simple.