Today, Julpan (a stealth-mode search engine) announced it is being acquired by Twitter. (see TechCrunch coverage)
There are not a lot of public details, but here are a few.
Julpan is a real-time search engine based in NYC. It focuses on analyzing social and real-time information from news, Twitter, and other sources. It was founded in mid-2010 by Ori Allon. Ori is an Ex-Googler from the search quality team (Google acquired his patented thesis work called Orion, see the Google feature post.).
Sadly, pending the integration with Twitter, the Julpan search products (Newsgrep and LiveBite) are no longer available online.