Zero dollars down, Simple Choice and Jump? T-Mobile must be downright crazy! Either that, or it's a carrier struggling to make a serious impact on a market dominated by two juggernauts -- juggernauts who also came out with early upgrade plans of their own within a week of Jump's debut. T-Mobile's "back at it," according to its press material, dropping the entry price on a slew of devices down to zero, effectively spreading out the payments over 24 months. All told, the promotion includes smartphones, tablets and hotspots, and is open to folks who are "well-qualified" (check your credit statements if you have any questions on that front). The deal starts tomorrow and runs for a "limited time." Unsurprisingly, there's also some fine print attached (e.g., the 32GB and 64GB iPhone 5 isn't covered). The carrier's site can break down all of that for you, and there's also more info to be had in a press release after the break.