T-Mobile's Android-based G1 handset has all the features of a smartphone but, with a focus on the mobile internet, it seems more akin to Nokia's Internet Tablet devices than as a rival for Apple's iPhone.

Although not available until November, we had the chance to get a quick look at the G1 at T-Mobile's launch event.

The device is similar in size to the iPhone, but heavier at 158 grams, and has a 3.2in touch-driven display with a resolution of 320 x 480 pixels.

The real novelty of the G1 is the Google-developed Android platform itself. The user interface looks very clean, with the home screen showing just a clock, a phone dialler, Contacts, Browser, Maps, Gmail and a link to T-Mobile's Web'n'Walk service.

Users can customise this home screen by simply moving the elements around with their finger. We found the device very responsive in our brief use of it.

The browser allows you to zoom in and out to view an entire web page or just a small section. In addition, it shares some similarities with Google's Chrome browser, in that users can open multiple web pages which are displayed as tiles within the browser window. Tapping on one with a finger zooms in to that page.

According to T-Mobile, the idea behind the G1 is that it is a web-based communications tool with a Mail application that keeps synchronised with a user's Gmail account, plus instant messaging.

For this reason, the device has a Qwerty keypad, revealed by swinging the screen out in an arc. Another unusual feature is that the G1 has a miniature trackball, akin to that of RIM's Blackberry Pearl, in the middle of the buttons beneath the screen.

Because Android is also designed as an 'open' platform, users will be able to download extra applications to the G1 from an online channel called Android Market.

Although available initially on a consumer tariff, T-Mobile's head of internet and entertainment Richard Warmsley said that there is no reason why it could not be used for business purposes.

He said he expected to see applications to link the G1 and other Android-based phones with Microsoft Exchange email systems before too long.

The T-Mobile G1 has HSDPA up to 7.2Mbit/s and Wi-Fi for fast browsing, and also has built-in GPS supported by the latest version of Google Maps.

One special feature that we did not get to see is the Digital Compass, which T-Mobile said works with Google Street View to give a 3D representation of the street you are on if you tilt the phone up.