We went through quite a few design iterations of the applet, here is the evolution:
There are still a few loose ends in the applet (clicking on the scroll bar doesn't work most of the time, since scrollbar was never meant to be inside menu, and therefore isn't trivial to fix), and it could also use a global hotkey to popup the search. But even now I find it very usable if one has enough stuff logged by Zeitgeist.
Since Seif still thought that standard Sezen window is the way to go (with which I obviously don't agree), there's also another version of the applet, which just opens undecorated Sezen under the menu item position:
Now I wonder about the future of the applet, should we try to fix the issues it has and push it upstream, or turn it into a widget which any app can use (it'd just tell us which mimetypes it's interested in and it would augment the "Open file" function). Also which version is really better? (but please judge by using them, not by looking at the screenshots)
Links to get the code:
To install you need to get the branch, its dependencies and run:
./autogen --prefix=/usr && cd sezen && make && sudo make install
Of course you should substitute the "sudo make install" with your distro's equivalent.
PS. For those interested here's my GSoC report for this week: http://mail.gnome.org/archives/gnome-soc-list/2010-July/msg00050.html