A slight upgrade to the Dopod D810, (now re-branded as HTC after a takeover), HTC has fitted the p3600i with the Windows Mobile 6 operating system, but it retains most of its brother's features – headed by HSPDA-connectivity, a built-in GPS receiver, 802.11g Wi-Fi and Bluetooth.

The p3600i is a quad-band GSM (850/900/1800/1900), tri-band 3G (850/1900/2100), GPRS and 3.5G HSDPA capable smartphone. It performs quite well for voice calls, with reasonable in-call quality, but we found the volume a little soft. Being a 3G handset, the p3600i is capable of video calling thanks to a front mounted VGA camera.

Running the latest Windows Mobile 6 operating system, the p3600i has Office Mobile, consisting of mobile versions of Microsoft Word, Excel and PowerPoint applications. There is also Windows Live, Internet Explorer and Windows Media Player programs. Both the built-in 802.11b/g Wi-Fi and the GPRS/EDGE wireless functionality make the p3600i an excellent e-mail device. The standard Windows Mobile messaging application supports push e-mail from a Microsoft Exchange mail server, as well as standard POP3 and IMAP e-mail accounts (Hotmail, GMail and Yahoo!). Connectivity is in the form of Bluetooth 2.0 (with support for A2DP) and USB 2.0. Unfortunately, the media support is let-down by a mini-USB headphone jack instead of the standard 3.5mm.

Updating from Windows Mobile 5 to 6 requires increased performance and HTC has installed a faster processor – 400MHz over the previous 200MHz. Performance is notable with minimal delay when switching between applications, though some parts of the Windows interface are still sluggish. Also under the hood are 64MB RAM and 128MB flash memory. A microSD card slot is present in a convenient right-side location, covered by a plastic flap.

In terms of design, the p3600i is finished in an attractive, gloss black plastic, which makes it a real fingerprint magnet. Usability is great thanks to the three-way scroll wheel. Scroll up and down to move through menu items and press in to select. The p3600i still includes a stylus and the standard array of buttons, but the scroll wheel makes navigation easy and effective.

Our review unit was fitted with the latest CoPilot Live 7 navigation software. The built-in GPS receiver worked well during testing, managing to maintain a relatively stable signal throughout our journey. You can read more about CoPilot Live 7 in our stand-alone review.

The 2-megapixel camera takes decent, but far from outstanding photos. The lack of flash or light means night-time photography is virtually impossible though. The front mounted VGA camera can double as a camera for portrait photos. Video recording, panorama, burst and sports scene modes and a two- or five-second self-timer are other features.

Battery life is excellent according to HTC's figures of the eight days standby time and over four hours of talk time – impressive considering the specifications and capabilities of this device.