The BlackBerry Curve from Research In Motion (RIM) expands the BlackBerry family with an easy-to-carry, compact device that retains the qwerty keyboard of larger designs. Although it ships with some consumer features, the Curve is one of the best designs RIM has produced.

Available now from O2 and Vodafone, the Curve has all the essential features of a BlackBerry - an excellent colour screen, qwerty keypad and access to push email - but in a slightly smaller format. However, the device still only supports GPRS networks (with Edge capability, where available), while many rival devices have 3G broadband and Wi-Fi.

On paper, the Curve is not actually much smaller than earlier models, such as the BlackBerry 8700, but in shaving a fraction of an inch off the width, height and depth, RIM has made it noticeably more compact. It is also about 20 percent lighter at 111g, which makes a real difference when carrying it in a pocket.

Despite its size, the keypad of the Curve is well-suited for thumb-typing, although workers used to the larger keypad of earlier devices may find it a little cramped. We found we could key in text at a reasonable speed without making too many mistakes. The Curve now also features a spell check function.

The Curve is equipped with RIM’s miniature trackball design, first seen on the BlackBerry Pearl, instead of a thumbwheel. This enables speedier navigation but we found it tiring to use for long periods. The BlackBerry key alongside it brings up a context-sensitive menu, while another key to the right serves as the cancel/close function.

The Curve, because of its smaller size, is likely to be used as a phone as well as an email client. Previous models were sometimes seen as too bulky so workers would often carry a phone as well as a BlackBerry.

RIM’s phone interface perhaps lacks some finesse when compared with other smartphone platforms. However, the Curve comes with RIM’s voice dialling application and is a quad-band handset capable of roaming to most countries.

The Curve’s more consumer-oriented features include a digital camera and an enhanced media player for audio and video content. The latter is backed by a new Windows desktop application for managing media files on the device. The two-megapixel camera takes reasonable quality shots and users can email or MMS images direct from the application. Both features can be disabled by policy settings from the BlackBerry Server if necessary, according to RIM.

An updated version of the BlackBerry Maps application makes it easier to find directions. However, unlike the larger BlackBerry 8800, the Curve does not feature built-in GPS hardware. This capability can be added through the Curve’s Bluetooth interface, which also supports wireless headsets.

The life of the Curve’s 1100 mAh removable battery pack is 17 days on standby or up to four hours of talk time. A MicroSD card slot behind the battery lets users expand on the 64MB of built-in Flash memory.