Writting a "search engine" for a pgsql DB

Hi all,

   I am asking in this list because, at the end of the day, this is a 
performance question.

   I am looking at writing a search engine of sorts for my database. I 
have only ever written very simple search engines before which amounted 
to not much more that the query string being used with ILIKE on a pile 
of columns. This was pretty rudimentary and didn't offer anything like 
relevance sorting and such (I'd sort by result name, age or whatnot).

   So I am hoping some of you guys and gals might be able to point me 
towards some resources or offer some tips or gotcha's before I get 
started on this. I'd really like to come up with a more intelligent 
search engine that doesn't take two minutes to return results. :) I 
know, in the end good indexes and underlying hardware will be important, 
but a sane as possible query structure helps to start with.

   Thanks all!!

Madison