Myspace is good for a couple things.
Number one, you keep in contact with people that you otherwise might not- friends who have moved away, are in the military, etc. You lose phone numbers and shit, but that page is always there.
Number two, women use it exclusively to keep in contact, so girls that you may have never talked to again will find you on myspace or vice versa, and you can keep in light contact until you want to move on it. I think of it as kind of a bullpen for women. It has worked for me in that degree also.
The third and final good thing is that after you hook up with a broad after you've been drinking, you can check her myspace and see if she was actually good looking or if you were just plowed. There were a couple times that I would have called the girl and gone out again, but then looked at her page and said, "Fucking christ, uh uh."