If you speak of Facebook, I heard, I joined....and have made no use of the thing at all.
But I spoke not of Facebook. I spoke of Twitter.
I saw Robert speak of it, I think, and heard it being hyped, so I went and had a look.
I saw nothing I wanted to be part of, so I didn't join.
Likely these things might be useful if you had friends who were part of the thing, but mine aren't at all.
I do hear colleagues babbling about Facebook at work, and they have put me off more...I would almost prefer them to babble about celebrities and such.
I am sure people CAN and do use these places to good effect, but when you look at them they seem utterly mindless and boring.