A place where people who never talk to you in real life add you so that they will have more "virtual" friends.
It is also a place where people upload hundred's of photos of themselves in the hope that someone may think they're cool.
Dave: wtf? how does she have 2000 facebook friends, she doesn't even have any real life friends
Mary: I'm going straight home to upload these photos to my facebook. I'm soooo cool!