Lie about your age?
You know, there's a reason why Facebook does not accept people below the age of 13. Those social networking sites can be very dangerous if your profile info gets into the wrong hands. For now, just stick with using a phone to contact others. Those sites aren't all they're hyped up to be, anyway.
Facebook is meant only for people who are 13 and above
Not that I know of, for Facebook, you can't be under 13, and I think that's the same for Myspace too. Anything els is probably cheep, and not secure.