I don't mean to sound elitist, but there are ALREADY sites that anyone can join and meet people. If I wanted that, I would have a MySpace account. I have a Facebook account because it is (or was) the only site that allowed me to meet only people I feel some connection to and community with. PLEASE do not open Facebook more than you already have!!!
Facebook was created as a means for college students to connect and keep in touch. Opening it up to the public would detract from its uniqueness. Furthermore, if it were open to the global community.. imagine the magnitude of stalking that could happen!
Facebook started in the Ivy League for Christ's sake. Stay elitist and proud! If I start getting lewd messages from creepy strangers or solicitations to join webcam voyeur groups, Facebook is dead to me.
One of the great things about facebook is that it isn't open to every single internet user, so all that myspace-esque shit doesn't happen. Let's keep it that way.