This is easy but there are many competing and contradictory instructions on Facebook’s Help site, so I thought I’d just lay it out for you.

To create a vanity URL, or a short URL, for either your Facebook Profile Page or your Facebook Page (or a business or organization), go to:

http://www.facebook.com/username.

You can set your Profile Page URL at that link. To set your Facebook Page URL, click “Set a username for your Pages.” This will list all the pages in which you are the admin.

There are a couple limitations:

• Your Facebook Page must have at least 25 fans. Your eligibility happens immediately when you hit 25 fans, so encourage people to recommend the page to friends to get you to your 25 fans.
• Your URL can only have letters and periods. No hyphens or other symbols.
• Once you set your short URL, it cannot be changed. So be sure it’s correct and what you want.

Just like domains on the internet, the good names are getting taken quickly. So go get one.