Native Mac theme
A frequent comment I get is that the GTK+ OS X screenshots look like... GTK+. As opposed to native Mac applications, of course. I started a native theme engine quite a while ago but got sidetracked with other things, so it's been sitting around in a git repo for some time now. It could be a fun hack if someone wants to get involved in GTK+ OS X hacking, and there is plenty of low hanging fruit to take care of. It's quite rewarding to play around with, as the result of the work is so immediately visible.
You can check it out here:
svn co svn.gnome.org/svn/gtk-quartz-engine/trunk gtk-quartz-engine
Here's an example of what it looks like on 10.5:
Update
The repo was moved to GNOME subversion, I've updated the info above to reflect that.

