Today I was looking for a nice search engine for my documents (no, I don't want to use some fancy desktop-search like Beagle, thanks). I was thinking about doing this a long time ago, and back then the only free engine was ht://Dig. And to be honest, back then it just sucked. Maybe it was the engines fault, maybe I was just too stupid to set it up correctly.
Nowadays there seems to be quite a bunch of available engines to choose from — here's a list with those I found.