I didn’t get to do much for Yahoo Hack Day, but I did get to help a coworker a teeny bit with an implementation of Y! Search for social web sites, including Facebook. There could be some interesting repercussions from that, so I won’t say more now. But what did surprise me is how many Yahoos are active on Facebook.
Myself–I’m still a Facebook curmudgeon. But mostly I simply haven’t had the time to check it out, or figure out the value proposition of accepting an invitation. -m