MySpace is a website founded in 2003 by neoconservative pedophiles in order to have sex with 13-year old girls. It requires you to fill in tons of personal info including credit card numbers and exact street address in order to join. Once you join a million people you don't know will know your personal info and give you prank calls and send hitmen over to your house. Also, your inbox will be filled with spam and friend requests promising you free p0rn if you add ILIKEKID4SEX as your friend.
So we've warned you. Facebook is better and has more cool stuff anyway.