Cognitive SEO has published a infographic which highlight the Blekko story. From CongnitiveSEO's post:
"We will tell you the long story short about Blekko, one of the new comers in the Super-Competitive Search Engine space.
If you already know Blekko then the infographic will give you a clearer overview about it & clarify most of your doubts.
If you don't know Blekko, then surely this graphic will give you the best possible insight about the new search engine."