OQO has announced its first ultra-mobile PC with built-in 3G cellular data. Aimed specifically at the UK market, the OQO e2 is a full Windows Vista-capable PC that includes a 3.6Mbit/s HSDPA modem, plus Wi-Fi and Bluetooth.

The device is about the size of a paperback book, but heavier, and will sell in the UK through Expansys at around £1290 including Windows XP -.about £170 more than a non-cellular version. It features a 5-inch 800 by 480 pixel WideVGA screen, a 1.6GHz low power VIA processor, and a full ASCII keyboard that slides out from under the screen.

When the keyboard - which includes a thumb-operated joystick - is closed, the e2 works as a tablet PC. It has touch-sensitive horizontal and vertical scrollers in the screen frame, and can also be used with a pen - it has to be an active stylus though, as the screen is not touch-sensitive.

The e2's 3G modem will fall back to UMTS or GPRS where HSDPA is not available. OQO CEO Dennis Moore said that this version will not be sold in the US: "3G wireless has spotty coverage in the US, but it's great in Europe," he noted, adding that versions for other European countries would come next.

The device cannot be used as a mobile phone for voice calls, though Moore said it could for example be used with a headset for VOIP, over WiFi or a 3G connection.

He added that the e2 will sell here network-unlocked, and with or without a wireless contract. That's unlike the US, where the equivalent model features an EVDO data modem and is sold with a Verizon or Sprint connection.

"There's so many carriers to certify with here in the UK," he said. "In the US you need that relationship, but here we can be in the market without that."

Non-cellular versions of the OQO e2 have been available for some weeks. Moore said that integrating the extra radio had presented challenges, especially in such a small format.

"It's combining all these radios and antennae that made it hard to do," he added. "You can get simultaneous operation of Wi-Fi, Bluetooth and 3G, and next year there will be GPS too."