I got sucked into Facebook recently and I have spent a lot of time browsing through the profiles of friends, classmates, schoolmates, old acquaintances, new ones, etc., etc. It is amazing... not the amount of time I have wasted (that is absolutely standard and unsurprising), but I'm talking about the Facebook phenomenon. I must say Cheers! to Facebook's creators they had the Vision and they were able to pull it off with style.
So forget other networking sites.. Facebook is the place to be.