Looking for a cell phone that combines unique design with a good dose of functionality? Here's one to add to your list: the Pantech Duo from AT&T Wireless. Business users will appreciate its good selection of office software and messaging options, while its cool, dual-sliding design will keep gadget lovers entertained--so long as they can stand the spotty sound quality.

It's one of the most compact keyboard-capable PDA phones I've seen. It weighs just 3.9 ounces and measures 4 inches high, 2 inches wide, and 0.8 inch thick--about the size of a bar of soap. At that size, a phone sporting an integrated QWERTY keyboard is impressive. Even better is its dual-sliding design: Sliding the front panel vertically reveals the alphanumeric keypad, and sliding it to the right uncovers the keyboard. Although we've seen this design from Pantech before with the Helio Ocean, the Duo is noticeably smaller than its older cousin.

Granted, small isn't always best. Some users may find the Duo's keyboard a bit cramped and too flat, though I found it easy to use. Similarly, the phone's 2.2-inch screen is not ideal for viewing text-heavy documents.

The Duo runs Windows Mobile 6 and--despite the limitations of the small display--it's nice especially in urgent situations to have the option to edit Word documents and Excel spreadsheets, as well as to view PowerPoint slides and PDFs, on the phone. Performance, overall, was great; the Duo felt speedy in nearly every app I used.

E-mail handling was fair. Using the AT&T XpressMail client, I wirelessly synced two of my personal e-mail accounts by following the step-by-step instructions on the phone. (It supports POP3 and IMAP e-mail, covering many nationwide ISPs, including AOL, EarthLink, and NetZero.) Oddly, Hotmail is available only through the Web browser, not on the phone's e-mail client.

You can send and receive corporate e-mail (Microsoft Exchange or Lotus Notes) as well. The setup requires downloading software on your office PC and then setting up e-mail on the phone.

I used the supplied USB cable and installed the bundled ActiveSync software on my PC to synchronize my Outlook calendar and contacts from my office PC to the phone. The initial setup was time consuming, but subsequent syncs were less taxing. If IM-ing is your thing, you'll find the preinstalled AIM, Windows Live Messenger, and Yahoo Messenger clients useful.

You don't get Wi-Fi or GPS with this phone, but you do get a fairly reliable 3G antenna. The voice and data signals in San Francisco were okay, but the phone's sound quality was subpar; I heard a hiss in the background during many of my calls. AT&T claims that the battery will provide up to 3 hours of talk time; in our lab tests it was slightly better, lasting 4 hours, 46 minutes--that's poor compared with other PDA phones we've tested, though.

The Duo's features aren't all business. The phone also includes a 1.3-megapixel camera for photos and video clips, a microSD memory card slot, and a 3.5mm headphone jack.

With its dual-sliding design and its smart combination of office and multimedia features, the Duo proves that you don't always have to trade form for function. The Duo gives you both.

--Grace Aquino