The Treo 600 from Handspring - now part of PalmOne - is a Palm-based smartphone that offers firms a serious alternative to Microsoft or Symbian handsets for equipping mobile workers.

Like other smartphones, it combines voice functions with email, web browsing and personal information management (PIM) tools, and the functions are well integrated and easy to use. The Treo 600 also includes a mini qwerty keypad, which makes messaging easier.

Available in the UK from mobile operator Orange, The Treo 600 is midway between a mobile phone and a PDA in size, closely matching Sony Ericsson's rival P800 device. At 168g, the Treo is slightly heavier than the P800, but it can still be carried comfortably in an average jacket pocket.

In tests, we found the Treo 600's features easy to get to grips with. Anyone familiar with Palm-based handhelds will have no difficulties, though people more used to Microsoft-based devices may take a little while to adjust.

A phone button below the Treo's screen launches the Orange home screen. From here, the user can dial using the Treo's keyboard. Users can also dial by selecting a name from the contact list, to which the home screen links.

During a call, on-screen buttons offer context-sensitive options. These include the ability to put the call on speakerphone, or to put callers on hold and dial another contact. Users can also make conference calls with up to five others, but this featured must be activated by calling Orange.

The Treo 600 has a built-in email client that can connect to POP3 mail servers only. This means it can link to Microsoft Exchange server, but not others such as Lotus Notes. Likewise, the Treo can be synchronised with a desktop PC via a HotSync cable connection, but only Microsoft Outlook or Palm's Desktop PIM tools are supported; users of other groupware applications must use third-party sync tools.

A view-only copy of Documents To Go from DataViz is supplied on CD-ROM. Once installed, this integrates with the email client and lets employees view Word and Excel attachments from within the inbox. The full version of the software enables users to edit these files.

For web access, the Treo 600 ships with version 3.0 of Handspring's Blazer browser. This reformats web pages to fit the small display, so the user only has to scroll up and down. We found this browser generally worked well, but sometimes garbled complex pages. Browsing via GPRS was slow in the congested airwaves of central London, but out of town we found pages loaded at about the same speed as they would via a dial-up modem connection.

The Treo's mini keyboard takes up an inch of space beneath the screen and navigation controls. The keyboard may be too small for some people, but we found we could enter text at a reasonable speed by cradling the device in both hands and typing with thumbs. One irritation is that some characters, such as the underscore common in email addresses, can only be entered from a drop-down list.

The PDA functions of the Treo 600 can be used with the phone turned off to conserve power. There is also a handy button to turn all sound off, which could be used to stop the phone ringing during meetings. The Treo has a 640x480 pixel digital camera, and images can be emailed directly from the camera application.

Battery life is rated at six hours of talk time, and up to 10 days on standby. Orange supplies the Treo 600 with a 32MB SD Flash card for extra storage.

Price: £199.99 + VAT with Orange GPRS contract

Contact: Orange 0500 802 080