Soon you will be able to have a username
Starting on Saturday, June 13th, at 12:01pm in your time zone (GMT +8), you’ll be able to choose a username for your Facebook account to easily direct friends, family, and coworkers to your profile.
Check out the Facebook Blog for more information.

There’s less than a few hours left to claim your own http://www.facebook.com/username URL. If your name is publicly general, e.g. John Smith, then please sit tight and make sure you’re the first one who submit your claim as they’re doing it on a First Come First Serve basis. So if your name is John Smith, like a few thousands more out there, you better make sure you’re the first, or you’ve gotta settle for http://www.facebook.com/johnsmith2 or 3 or 4, or maybe other nicknames.

Claim your Facebook username url at http://www.facebook.com/username. Good luck in claiming your own name!