Yahoo opened its corporate headquarters to hordes of hackers, press and others on Friday and Saturday for its open Hack Day. After 24 hours of hacking (with a break for a private Beck concert in the Yahoo courtyard the first evening), 54 projects were demo?d to the crowd of about 400 people. Over 3,000 pictures from the event (tagged ?HackDay06″) are on Flickr here. A handful of teams were awarded prizes in categories ranging from ?Too Useful? and ?Best Schtick? to ?Overall Winner?. The overall winner, determined by a quick huddle of judges after the demos (David Filo, Jeff Weiner, Ash Patel, Bradley Horowitz, Chad Dickerson, David Hornik, Peter Fenton, Gina Trapani, Salim Ishmael and me) was a hardware/software combination device stashed inside a woman?s handbag. The winning project, called Blogging In Motion, combined a camera, a handbag, a pedometer and the Flickr API to create a device that takes a picture after every few steps and then automatically blogs those pictures. The device was created by Diana Eng, Emily and Audrey, pictured to the right along with the device (I?m still tracking down Emily and Audrey?s last names).