Quadband support have you canceling your plans to pickup the HTC Touch Diamond here in the States?  Thankfully our friends over at Xda-developers have come through in the clutch with a way to enable the missing 850MHz band on the HTC Touch Diamond.  Before you break out the champagne and begin the celebrations you must know that this only turns the device into quadband GSM/GPRS/EDGE.  Simply put, you will not be able to make use of At&t or T-mobile USA 3G bands, only EDGE data speeds.

If EDGE data speeds will suffice then this cab is for you and a quick download and install should have you up and running in no time.  Once you complete the install you will now have the option in your phone settings to select the 850 + 1900 GSM band and thus enable full EDGE/GSM/GPRS connectivity on both T-mobile USA and At&t.

The bottom line is that this feature is more useful for the inbound roamer visiting the States with their HTC Touch Diamond and not the full time US resident.  If you plan on turning the HTC Touch Diamond into your daily device here in the US, HTC will be releasing NAM (north america) spec unit later this year on At&t, Verizon and Sprint.

Download the GSM 850 band unlock for the HTC Touch Diamond here.