Facebook is tapping the US mobile market by adding the same support that catapulted Twitter to widespread use, such as the ability to update statuses, receive mobile updates from public profiles, and even become a fan of a brand via SMS.

Mobile users can become a "fan" of a page by texting the name of the page to Facebook’s shortcode, 32665 - which spells out FBOOK, Mashable writes. (Twitter provides a similar application where it lets users text "follow [username]" to their short code – 40404.)

For example, to become a fan of Canadian yogawear company Lululemon, you would text "fan lululemon" to the number. You won't receive updates from Lululemon on your phone - but that will be the next step, and will arrive soon, according to AllFacebook.

The new mobile support, which does include the ability to send and receive personal updates, is still in beta, and hasn’t been enabled for every Page yet, so administrators of the page should check their settings to see if they can add mobile support.

Also, Facebook users must set up their mobile phone to receive texts from Facebook in order to successfully opt-in to mobile messages.

But marketers are already raving about the "text to fan" feature and its potential impact on brand-following on Facebook. The prospects are promising: a company CEO, marketer, employee, or brand supporter can ask people to become fans even while they are offline; politicians might use the channel to rally votes in some sort of protest or mass gathering.

And company marketing collateral - brochures, commercials, print ads, websites - can include instructions on how to become a fan via SMS.

For Facebook, more fans will mean more traffic and user involvement, which is welcome: Twitter's user base vaulted from about a half million in Feb. '08 to seven million last month - a year-on-year growth rate of 1,382%.

What will Facebook have to do next to finish handling the Twitter threat? API access to Facebook public profiles, which will include unlimited access to status updates and comments, AllFacebook suggests.