good luck w/ your site but your dreaming if you think you will get as much traffic as myspace/facebook

i'm sure you will have some smart ass remark for my criticism but i do web development for a living and everyone wants to be the next myspace/facebook. you may have some great unique idea but trying to duplicate major sites will not take away from their traffic but increase it. no one builds over night a 50+ million dollar site.

good luck w/ your website - if you need some developer contacts let me know i know some freelance guys who maybe able to help.