No, I wouldn't buy them and don't own any.
I think it's way too early to get into tech stocks. Back in the 90s, some people I knew lost most of their 401ks fooling around with them. One of my bosses lost a hundred grand overnight. So much of it is hype and ego, and remember My Space? Prodigy Bulletin Boards? Yahoo message boards? Who uses these things now? Who cares about them at all?
Right now, all these big players are trying to guess what is coming next and be the first one there. I don't think Facebook will win that game. Or at least, I hope it won't.