Searching gets smart filtering
This is damn cool. Google-enabled 'search my trusted universe' tool. When you start cascading it, you will *really* have something: "Search my trusted universe, and the trusted parties of my trusted universe, unto three degrees of separation. Go forth, my spider."

How to add it to your site:
http://www.alpern.org/weblog/php/blogsearch/mysite.php

How it works:
http://www.alpern.org/weblog/php/blogsearch/writeup.html

I found it on Kevin Werbach's site (he's implemented it) and followed it back to the source. Excellent.