I use it for keeping up with new/old friends.
And stalking exes.
J/K
Seriously though. As long as you don't "like" everything under the sun, keep all your sh*t to "private," and dont download any apps, you're good.
Social networking is getting crazy. I've seen rumors of a "Facebook score". Kind of a data gathering program that people can use to determine seating arrangements on planes and such. Wonder where they will draw the line. Sorry, but I won't take the mark of the beast.