You've gotta go visit (then bookmark!) Taaz.com. It's the best virtual makeover site there is, allowing you to test-drive new hair colors, a different hair length, and even makeup colors and techniques! They've also got a well-done Beauty and Style section with tips and tricks to get your real you even more gorgeous in no time!
I decided to try on a chocolate rocker shag a la Taylor Momsen (hers is peroxide blonde but I wanted to take baby steps). I even played with colored contacts, which I really dig!