Sick of that iPhone and interested in switching to T-Mobile? It's the perfect time to do so, as the nation's fourth largest wireless carrier is offering a trade-in credit ranging from $100 to $350 (depending on the condition and model) to be used towards the HTC HD2. The offer is only available through the phone, non-corporate dealers, and the B2B channels. Your iPhone must be in working condition, but think of it this way - if you were to get the full $350 credit, it would pay for the device and most of the AT&T early termination fee.
The promotion ends on May 19th, so be sure to take advantage of the deal if you're interested (assuming they have the HD2 in stock)!