Last week, Facebook announced it would be offering personalized web addresses to its users starting on Saturday, June 13th.

Though permanent, the URLs are free and convenient: traits that have proven desirable to celebrities and giggling teens alike. In only 3 minutes, over 200,000 usernames were registered here.

In a way, Facebook is handing out billboards to its massive community of users, with results varying to predictable extremes.

Users were given free range within parameters such as the 5 character minimum, availability only to fan pages that are at least 1,000 strong, and that your username can’t be “/usernames”. One mischievous user forced them to add that last one a few minutes after opening registration.

Many have taken advantage of the feature for the Web site’s stated purpose: “to make it easier for people to find and connect with you.”

But while some hurried to reserve their own names, there is of course a more entertaining side to this double-edged sword. Other early adapters have chosen to use their space to pay homage to web jargon and viral memes.

The approximately 6 million addresses registered as of Sunday represent a fraction of the 200+ million worldwide users. However, a casual search of pop culture keywords will almost certainly yield the profile of someone who had nothing to do last Saturday night.

For example, /numanuma, /chocolaterain and /icanhazcheezburger have all been snatched up.

One lucky guy grabbed /loljk, irreversibly allowing an increasing number of people to know that he goes to Manhattan College, class of 2011. If life were a romantic comedy, perhaps he’d meet the California girl behind /roflmao in some lol-able twist.

Unfortunately this is the Internet, and it’s much more likely that /2girls1cup and /goatse.cx will hit it off. It’s best not to think about it.

As always, we can look to celebrities to distract us. For the first time in the history of Facebook, the best comparison is Twitter, which has offered custom URLs from the start.

President Obama and Oprah Winfrey both got their Twitter usernames (@barackobama and @oprah, respectively) reserved on Facebook too. Check /britneyspears and you’ll find it is indeed Britney, b****.

Even CNN got its act together and took /cnnbrk, although it only has 2 friends. And one is a cat.

The more amusing tales come from the slower celebs; for example, /therealshaq is an imposter. Also, remember how Ashton Kutcher had to settle for @aplusk on Twitter because @ashtonkutcher was taken? Someone beat him to the punch again, because Facebook is fresh out of both /aplusk and /ashtonkutcher.

People also snagged /johncmayer, /jimmyfallon and /theellenshow, which respectively belong to John Mayer, Jimmy Fallon, and Ellen DeGeneres on Twitter.

More exciting still are the popular Twitter names that have not been taken on Facebook yet. The following are still on the market as of early Tuesday: /algore, /tonyhawk, /petewentz, /ashsimpsonwentz, /gstephanopolous, /thatkevinsmith, /freddurst, /twitter.

Our Take:

When you do take one of those usernames, just remember that you heard about it here first. So if Al Gore offers you space in his apocalypse-proof underground lair in exchange for his username, I want in.

There has been a lot of criticism that Facebook is once again emulating Twitter or Myspace, but we’re more concerned that enforcing permanency on the profile will make people leave the site for good. Sure, “Johnny Dildoseed” can change his name, but he’ll be forever found at http://facebook.com/buttplug.