This is a new customizable vertical search engine that has the potential to be an extremely useful research tool. Its open crawl and ranking data policy should make it useful for SEO research.
The engine is currently in closed private beta. You need like them on Facebook or follow on Twitter to get an invitation. http://blekko.com/
[blekko.com] A new kind of socially-biased search engine: Blekko Robert Scoble's interview with Rich Skrenta and Mike Markson http://www.youtube.com/watch?v=tlESXiyyA5M