The HP iPaq hw 6500 Mobile Messenger has a built-in keyboard, Bluetooth technology and an embedded global positioning satellite receiver.

Atlanta, Georgia-based Cingular will be the sole US carrier for the device beginning October 31.

Palo Alto, California-based HP and Cingular said they were working with 14 software vendors to develop mobile applications, including email, security, messaging and GPS navigation. Beta versions of some of these applications can be downloaded.

The device will cost $499 with a two-year contract, plus $39.99 per month for unlimited data with a voice plan.

Cingular, a joint venture between SBC Communications and BellSouth, will sell two versions of the device, the hw6515 with a 1.3-megapixel camera and the hw6510 without a camera.

Cingular’s Edge network is the largest wireless data network in the US and covers 13,000 locations. However, No 2 Verizon Wireless, also a joint venture (between Verizon Communications and Vodafone), has lately been gaining market share.