Collaborative filtering

Hullo.

I wonder if anyone has any experience of doing collaborative filtering
in Perl (or anything else, for that matter). As I understand it,
AI::Categorize can categorize items which are similar to items that
are already categorized. I have a big database of 100,478
(http://astray.com/recipes/) and would like to offer a "recipes which
you might be interested in" link. Has anything been done like this for
opensource recently? I can only find dead projects using Google /
Citeseer.

Cheers, Leon

ps oooh, good random tagline
-- 
Leon Brocard.............................http://www.astray.com/
Nanoware...............................http://www.nanoware.org/

.... A living example of Artificial Intelligence