Back at CTIA 2010, Motorola announced the world’s first rugged Android handset with iDEN push-to-talk functionality: the i1. At launch, Motorola was only willing to spill the beans on one carrier who’d be getting the handset: Sprint.

We just unearthed some pretty irrefutable proof that someone else will be getting the i1: Boost Mobile. Yep — say hello to the first pre-paid Android handset in the US.

One of our oh-so-lovely tipsters just sent over the poster you see below, from which a few details can be gleaned: the Boost Mobile i1 will launch with retail exclusivity at Best Buy, and it’ll be Boost’s first Android phone. Better yet, it looks like Boost will be offering this handset with their standard $50 unlimited data/web/text plan — in other words, they’re not going to try to strap on some crazy smartphone tax.

Given Boost’s current line-up, this will very, very easily be their best offering. There’s no word yet on pricing — but remember, there’s no contract here, which means no subsidies. The Boost BlackBerry 8330 costs $249.99 out the door, and it’s a pretty safe bet to wager that the i1 will cost at least as much.