Powerful laptop computers are often dubbed “desktop replacements.” A new feature-rich smart phone may coax people to swap out their laptops as well.

The PPC 6700 from Sprint PCS is the first cell phone–PDA hybrid available in the United States that runs Windows Mobile 5.0, Microsoft’s latest handheld operating system. (Qwest and Verizon Wireless also offer the device as the Pocket PC 6700Q and the XV6700, respectively.) The software includes versions of popular office programs, including Word, Excel, PowerPoint, and Outlook. It also supports wireless synchronization of e-mail and calendar content between the phone and a PC.

The six-ounce device, produced by California’s UTStarcom Personal Communications, has a 2.8-inch color screen, takes digital photos and video, and is compatible with several wireless technologies. You can get on line via your cellular carrier’s wireless data service, or if you’re in an airport or coffee-shop Wi-Fi “hotspot,” you can tap into that network. Built-in Bluetooth technology allows the use of wireless headsets and other accessories.

The keys to this smart phone’s appeal, however, may be the ones that slide out from its side. The full “qwerty” keyboard is larger and more like a laptop’s than the miniscule button sets found on other handhelds.

Prices range from $400 to $520, depending on the service agreement you choose. Sprint and Verizon offer faster wireless data speeds, while Qwest can let your cell phone and land line share a single phone number and voice-mail box.