T-Mobile definitely has some tricks up its sleeve this holiday season as we just received word that retail stores are offering a buy-one-get-one free special for any smartphone. You heard us correctly: any smartphone. All you have to do is activate two new lines to qualify for the promotion. This means you can pick up a BlackBerry 9700 and get a myTouch 3G for free, or buy a Touch Pro 2 and get a BlackBerry 8520. Or buy a Sidekick… just kidding. But you get the idea. Before you send us a flood of hate mail, this offer does vary region by region. For example, T-Mobile retail stores in NYC are definitely offering this promotion, but stores in L.A. are not. However, some retail stores said they’re always willing to price match competitors and other T-Mobile locations. All you need is proof that other retail stores are offering this promotion because some stores haven’t heard of this, and that shouldn’t be too difficult. Let us know how it goes for you!