Should I get on LinkedIn? One hears far less about what they're up to than Facebook, and I recently received an invitation from a friend of mine.
Less subjectively: What does LinkedIn offer (given that it's a social network site), and do you find it worth your time?
Update: I signed up. No especially noticeable effects so far other than one newsletter sort of mailing and a lot of people I know wanting to add me as a contact^Wconnection; presumably LinkedIn notifies you when people in your address book create an account?