T-Mobile has announced a new Pocket PC-based smartphone called the MDA III, the sequel to the MDA II. The MDA II is also offered by O2 as the XDA II and is actually a smartphone called the Himalaya built by Taiwanese handheld specialist HTC.

A few details were released about the upcoming MDA III. It is known that it will feature the traditional tablet Pocket PC design. However, the MDA III takes a page out of palmOne's playbook with a slider that reveals a QWERTY thumb-keyboard when open.

When closed, the unit measures 4.9 x 2.75 x 0.75 inches and weighs about 7.4 ounces. The operating system will be Windows Mobile 2003 for Pocket PC Phone Edition. And the device is slated to last 25 percent longer on its battery charge than the MDA II.

Other features of the MDA III include a 3.5-inch display that supports the Pocket PC standard 240 x 320 resolution, an SDIO-enabled Secure Digital card slot for memory and peripheral expansion, 128MB of RAM, a 400MHz Intel XScale CPU and a integrated 0.3 megapixel camera for taking VGA or 640 x 480 pixel resolution pictures.

Interestingly, it doesn’t look like the MDA III will integrate Bluetooth, so users won't be able to use the device with wireless headsets and printers, among other Bluetooth peripherals. The MDA II integrated Bluetooth.

Another important feature of the new smartphone is that it will also integrate 802.11b Wi-Fi with its cellular wireless voice and data capabilities. Several other smartphones due later this year will also add Wi-Fi. These include Hewlett-Packard's first smartphone, the iPAQ h6300 series, Nokia's 9500 Communicator series, and Motorola's MPx.

The MDA III should make its way to the German market sometime in September. It is not known if it will be shipping anywhere else, thought it is likely that other mobile operators in Europe will offer the smartphone.

As for the United States, rumors place a version of the MDA III called the PPC66600 as coming from Sprint later this year for its upcoming EV-DO network, which should allow for data transfers of up to 300 to 500 Kbps. The device, which was designed by Daxian Telecom, won't integrate Wi-Fi but will feature Bluetooth.