As I noticed today, the desktop-search Beagle seems broken (again) in Ubuntu Karmic Koala. The most annoying thing is that nothing tells you that it's broken. Only the fact that Beagle doesn't index a thing, no matter what you change in
beagle-settings, gives you a hint.
For some reason I don't even remember I've been a bigger fan of tracker anyway for a while. Installing on a fresh Karmic works like this:
sudo apt-get install tracker tracker-search-tool tracker-utils.
If you, like me, frequently use Deskbar, you might also want to install the package libdeskbar-tracker. This enables you to get search results from tracker as you type. If the tracker daemon does not start automatically, you can start it by hand running
/usr/lib/tracker/trackerd. To all I know the tracker applet also refuses to start, untill the daemon is up and running.