Actually, there are something like 9 of them out there at the moment. Charlie Arehart wrote up a blog post on them:
The House of Fusion search is integrated directly into the site so few actually realize that it’s a ColdFusion-centric search.
We’ve been working on a couple of Google CoOp engines as well —
http://training.figleaf.com/Resources/socialsearch/flash.cfm (includes flash 8 and flex 2)