Facebook is not a competition.
...neither is Myspace.
(i hate how people think that the number of "friends" they have online is a reflection of how cool they are as a person...)
i deleted both of my accounts like 2 years ago, and i seriously don't miss it at all.
it was so useless... and way too time-consuming.
so i decided that if (and when) i get on the internet, i'm going to be doing something more productive. like reading about personal development.
but even if you don't want to close down your account, i would still recommend taking a break from it... delete it from your Favorites, forget about it, and don't log in for at least a week.
who you are in real life is much more important than how you're portrayed on the computer, anyway.