Dan plays with the INQ-1 (aka the FacebookPhone)
Image by Cristiano Betta via Flickr

Facebook expands its battle plans to mobile apps and mobile phones, but it won’t be building a new platform or device, it’ll just open up what’s already working for it. But don’t hold your breath for an iPad app.

Mark Zuckerberg snuffed the hopes today of those who thought they might be getting a Facebook phone this holiday season. “There has been this rumor going around that Facebook is going to build a phone, what a novel idea,” Zuckerberg told a crowd of press, analysts and developers at Facebook’s Palo Alto, Calif. HQ Wednesday.  “No. If you are building the iPhone you want to sell as many iPhones as possible. Our goal is to make everything social.”

To that end, Zuckeberg and his mobile team outlined Facebook’s plan to make it easier than ever for Facebookers to use, and developers to deploy, social apps on every (smart)phone on the planet. Of course, those apps will be running on top of Facebook.

Sound familiar? It should, this is exactly the same strategy Facebook took with its web-based social network. By opening up Facebook’s mobile platform in the same way, Facebooks hopes it can similarly suck up all the time people spend doing things on their phones, and as the chart here shows, suck up the predicted advertising revenue growth on the platform. Already, Zuckerberg pointed out, there are more than 200 million people actively using Facebook mobile applications. “Think about that compared to other mobile platforms , Android or iOS,” Zuckerberg said.  “This is a much bigger platform than that.”

In order to leverage the growing legion of mobile Facebook users (their ranks tripled in the last year), Facebook is rolling out three key features.

1)   Single sign-on: You sign-on to Facebook once on your mobile phone, and any other Facebook-enabled  app you have on your phone you just click (or touch, more likely) and use. The example presented was using Groupon’s mobile app. Sign-in on Facebook, get an offer from Groupon for indoor-sky diving and simply buy it. No separate sign on. Sounds simple, but the idea is that it drives more usage of  Facebook apps and the time you spend with the world’s largest social network.

2)   Opening up its location API: Over the summer Facebook launched Places, it’s location-based check-in service. Initially it was read-only, which is to say Facebook had most of the control of the location data that users were generating. Facebook opened up the other side of it Wednesday — the “write” part. What that means is that any application can take advantage of the location data that Facebook users and apps generate.

3)   A local deals platform: One of the most promising use cases of apps running on phones are deals for local businesses and events. You have your phone with you, you want a frozen yogurt, or to hear live music, the phone is the perfect place to find a deal and then go out and buy it from the store offering the discount. Initial retail partners include retailers like Gap, REI, American Eagle Outfitters and Starbucks with others to follow. It’s the coupon-oriented, phone-based discount service futurists have long touted, and if any service has a chance of making it stick, it seems likely to be Facebook.

The bottom-line is that Facebook is charging as hard in the mobile world as it has in the notebook/desktop world. Zuckerberg and his crew want Facebook to be the hub around which all our online interactions occur. Again, it makes sense from a business standpoint, and will help Facebook’s revenue from advertising increase, too. It sounds quaint to even say, “online” interactions, because  for many people, it’s just become the normal way of interacting. So they want to be the hub around which we do everything — gossip, shop, share music and photos. Our phones are increasingly the place where these things are happening, and Facebook wants to own that experience. So does Apple AAPL , so does Google GOOG . Nokia NOK , Microsoft MSFT and Research in Motion RIMM would like to own it too (no matter how unlikely that the Blackberry maker can pull it off).

Facebook’s advantage is that it runs across all the various devices and operating systems made by those companies. Pushing hard into the mobile world without diving into hardware seems a very smart move, especially as Facebook’s mobile goodies get rolled out internationally, where the smart phone rather than the PC has been the main mode of computing and communicating.

So even if you don’t get a “Facebook phone,” odds are Facebook is soon going to be more prominent on the phone you have, and any phone you get in the future. But not your iPad, yet. In response to a question about when Facebook would have an iPad app, and why it wasn’t part of the mobile announcements Zuckerberg was succinct. “The iPad is not mobile,” Zuckerberg said. “Sorry if that offends Apple, it’s a computer.”