I have to admit, some of my more enjoyable time wasting on facebook comes from the “you might know” whack-a-mole.  Because if you decline people there it pops up new suggestions live.  Most of the time these people are in seperate social groups who I happen to have a few friends in, though some times I scratch my head about some of the people it thinks I should know, like people that I had no overlapping years with at college and no shared friends.  And, typically ever time I whack-a-mole long enough it finally pops up someone that I would like to add to my friend list.