Anik Singal over at Affiliate Classroom has utilized the new Google co-op search engine technology to build an affiliate industry specific search engine. You can check it out at Affoogle.com
You can see a full list of sites it pulls from here: http://www.affoogle.com/listed_sites.html and
it allows you to make suggestions as well. This execution reminds me a lot of Rollyo - a technology that lets you create your own search engine by combining several sites together.