I've implemented a search function into getnews. Currently, well it sucks! :p It can find some stuff but not everything. Also it only searches direct matches. I'll work on it a bit more later.
Linky:
http://blog.dalegroup.net/?newsid=find
It only searches the body of the news item (not comments, title etc). Still very much just playing with it. It also screws links if the search term is in a link. Okay so it is crap, but it is a one line query that I wrote. Get over it :p
EDIT: HA! I had something every stupid in my code which was restricting the search. It's working better now.