It’s Demo Day time once again for Y Combinator, the startup incubator that has become a Silicon Valley institution since shaping its first class of startups back in 2005. A handful of us TechCrunch writers are here in Mountain View, Calif, at the Computer History Museum, where the 47 startups that made up YC’s Winter 2012 class are set to pitch to a room filled with tech investors, executives and

