Developed with T-Mobile, the h6315 operates on a traditional cellular network but can easily switch over to a Wi-Fi connection, which is much faster. The device also boasts a built-in camera, detachable keyboard and can also "act as a cell phone using the GSM cellular network."

"This is the ultimate device," said Scott Ballantyne, vice president of business services marketing for T-Mobile USA. "This will play and store MP3s. It takes pictures."

Behind the scenes, the T-Mobile network had to be adjusted so that devices could store a second IP connection. There were also changes to the Windows Mobile operating system as well.

"HP plans to sell the 6315 model exclusively with T-Mobile in North America, although HP will also sell a version of the device in Europe and Asia that can be used with other carriers' networks.

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