With UMA, cellular/Wi-Fi handsets can integrate seamlessly and with minimal impact into a wireless carrier's existing core network infrastructure, while delivering better and more consistent service to end-users because calls can be carried over a WLAN (via VoIP) when cellular service isn't available. The technology also promises to deliver service over the type of network (cellular or Wi-Fi) that is cheapest and most available at any given moment.

(T-Mobile is the first mobile operator in the U.S. to deliver a dual-mode service currently - the $20 per month HotSpot @Home available on a trial basis in Seattle - that allows users to make cellular and Wi-Fi calls from the same handset. So they can be on a cellular call, using the minutes from their mobile plan, but when they walk into their home or in range of a T-Mobile hotspot, the call is automatically moved over to Wi-Fi without interruption.)

Due this spring from an as-of-yet unnamed carrier, for between $300 to $350, the new HP smartphone deviates from the computer and printer giant's usual design: For example, there's no QWERTY thumb-keyboard with the iPAQ 510. Rather, it features a candy-bar form factor with a numeric keypad.

The iPAQ 510 runs on Windows Mobile 6 with push e-mail and document viewing and editing capabilities. You can snap pictures and take video with its 1.3 megapixel camera. It tops out at 2.5G EDGE (no 3G) cellular-data technology, but, as indicated by today's Kineto announcement, there is Wi-Fi. Bluetooth is available to wirelessly connect to headsets and hands-free car kits.

It accepts over voice commands—to control and navigate through applications, for instance—and allows you to dictate text - e-mail for example.

HP promises up to six hours of talk time from the smartphone's battery.

Through technology acquired with its purchase of Bitfone, HP provides a number of over-the-air management and security features for enterprises, including remote wipe and application access.