AT&T Wireless and Motorola have announced the immediate availability of the first Microsoft-based smartphone to hit the US. In the past other companies have offered smartphones running Microsofts Pocket PC Phone Edition software, but this is the first phone to debut using Microsoft's Smartphone 2002 software.

The MPx200 uses a clamshell design with the keypad and buttons on one side and the screen on the other. It has a 16-bit color screen that measures 176 by 220 pixels.

The MPx200 has a 200 MHz Texas Instruments OMAP processor and includes 32 MB of RAM and 32 MB of ROM. It has an SD/MMC slot that supports SDIO, and includes a mini USB connection and an IrDA port.

The MPx200 measures 3.5 x 1.9 x 1.1 in. It includes an 850 mAh Li-Ion battery, which allows up to 3.4 hours of talk time and up to 70 hours of standby.

The MPx200 costs $300 and is available at AT&T Wireless.