Last year MySpace, this year Facebook... next year: who knows?
Social Networking sites seem to have a short shelf life.
I have a Facebook account... it's cool to hear back from old friends, but it's annoying when a couple people who are addicts post a million times a day about how they flushed their toilet or took some assenine quiz that looks like it was made by a thousand monkeys typing randomly for about 2 minutes.
Also, their security configuration needs to be improved and it also needs to get a LOT more user friendly.