Those with less than 1000 were out of luck, that is until last night (6/28/09) when Facebook opened up the selection process for Fan/Biz pages with less than 1000, but more than 100. That is an achievable amount, so start planning.
Firstly, if you have a personal page and you have yet to create a vanity url, go do it! You might wish you had done in the future. If you have a common name, you may have to play around with different variations. Next, if you have a Fan/Biz page, you must have at least 100 users. So if you don't have a Page, get one created and get 100 fans. After that, select a unique vanity url for your business and start advertising it whereever you would normally advertise your social media "handles."
That's it, it's simple to do and makes linking to your Facebook pages a snap!