The W580i offers a compact sliding motion model design, with a cramped but surprisingly user friendly button layout underneath. 

Impressively, this model of Walkman offers a built in pedometer, offering runners the option to track their distance on their phone, whilst listening to music on the walkman - It even counts the calories you burn!  Supported on the music player is album art and features a 5 mode equaliser, so you can fine tune your music to get the desired sound.

The internet browser on the 580i is impressive as well, offering a clever option to fit web pages onto the small screen.  Sony have included EDGE software on the phone, instead of 3G, which is slightly faster.  Ideally, if you want to use the phone for music playing, you'll need to get a bigger memory stick than the 512MB stick included with the phone.

The camera, on the other hand, feels more like a last minute addition, with no auto focus and no flash.  It also only boasts 2 Mega Pixel, which in this day and age is pretty standard.  As always, the battery life is what you expect from Sony - superb.