T-Mobile apparently has a trade-in program that may help those who can't decide what to do with that old iPhone. From April 1 through May 19, you can trade in an iPhone for up to $350 credit towards a new HTC HD2.

Participating T-Mobile dealers will be authorized to give a minimum of $100 credit (max $350) to those trading in their iPhones. The iPhone must be functional and in working condition; screen not broken, damaged or leaking; and no liquid damage or corrosion present. According to the details, activation is not required with the credit being applied to the fully priced HD2.

The HD2 is already priced extremely well and for those who have an iPhone lying around collecting dust (we're looking at you, CrackBerry Kevin), the trade-in program makes the HD2 even more attractive of an offer. [via tmonews]