My MySpace page I've had for a while, but aside from the occasional message of interest, I've never been overly impressed. The concept is good but it suffers from poor aesthetics. Saying that though I have been meeting folk through it, and have just updated it a bit.
bebo on the other hand I've only recently joined and am more impressed with. It's better laid out and looks better.
Update: Okay I'm gonna backtrack on what I said. Bebo is good and has its place, but currently I'm having way more fun with MySpace.