BarCampBlock was packed yesterday, with close to 1,000 in attendance. The session on Opening the Social Graph was packed, as expected. Brad Fitzpatrick (who is heading to Google), David Recordon (who is heading to SixApart), Joseph Smarr (Plaxo’s Chief Platform Architect), and Tantek Celik (until recently at Technorati) did a great job laying out the case for a new approach to assembling the social graph by traversing the linkages between various services. I assert that this is my blog, and on this blog, I assert that I am “johnmccrea” on Twitter, and so on. Using such information, a decent portion of the social graph (the public portion), can be stitched together by one or more entities, and then surfaced via APIs to a variety of social web apps. At one point, someone brought up Facebook. “Is anyone from Facebook here?” Silence. “Anyone?” Kinda odd, since the debate was taking place two blocks from Facebook’s headquarters.