You can now claim your Facebook Page address or vanity URL as it’s known before you’ve obtained 25 Likes for your Page. However, you can only do this if you’ve never claimed an address before. It’s not clear if Facebook has deliberately introduced this change or whether it’s just an anomaly.
So if you qualify as above or have more than 25 Likes then take advantage and claim an address that reflects your business name, is neater and easier to remember. Go to http://facebook.com/username to claim. Note that you can also claim your personal profile address here so make sure you are setting the address as required. That is, don’t set your Page name for your profile.