[batiudrami]

I don't think not having Facebook is antisocial in that it hinders others, but I think not having one hinders yourself socially (at least at my age - 21).

If people are having a non-formal invite (i.e. not a wedding or a 21st which will usually get a paper invite), the event invites are all done through Facebook. If its a close friend of yours, you'll get a text message anyway, but if it's an acquaintance, you might find yourself without an invite, whereas all your mates do. If you want to go, you have to get them to ask if you can come, sometimes an uncomfortable conversation.

I also find (though I only have a few examples), that those without Facebook like to complain that they're never invited to events yet like to maintain moral superiority over those who do.