blekko – SlashTag Search Engine
http://blekko.com/

blekko is a better way to search the web by using slashtags. Slashtags search only the sites you want and cut out the spam sites. Use friends, experts, community or your own slashtags to slash in what you want and slash out what you don’t. This has beeen added to the tools section of Research Resources Subjecvt Tracer™ Information Blog.