The evolution of micro-sized storage is one of the more significant technological strands of the decade, with a heavy impact on the wide range of devices. Solid-state memory continues to offer higher capacities for lower prices, but the physical size of hard disks are shrinking, which means they're appearing in unexpected places.

Case in point: Samsung's SGHi300, a mobile phone with a 3GB hard disk, based on a 1-inch cornice mechanism. It adds bulk to a slim case, but is far from a gimmick: hook up the accompanying USB 2.0 cable, and you can use the i300 as an external drive with your PC. Samsung's motivation for the unusual component is music: the disk enables the i300 to hold around 700 MP3, AAC or WMA tracks to enjoy anywhere, along with Windows Video. Storebought WMA with DRM protection is also supported.

A supplied adapter enables you to plug in 3.5mm headphones, so the audio quality is better than you might expect. Built-in Bluetooth means you can also use wireless headphones. The only penalty is battery life: make a respectable number of phone calls, and you may get only 30 to 60 minutes of listening time from a charge, relegating the music player to an occasional treat.

Taking a leaf from the iPod, the i300 features a scroll wheel control that also functions as a standard nineway navigation joypad. A discrete raised nub makes use natural, but menu selection feels arbitrary at times. It has a pleasant keypad, but enough side buttons to make you wary of holding the phone in case you accident activate something. But the pressure sensitivity is judged well enough for that to be unlikely.

The OS is Windows Mobile 2003, to which Samsung adds its own media player (pointlessly) and Piscel Viewer, which does a more accurate job of presenting Office documents than Windows' own tools. A display of 240 x 320 pixels presents apps crisply, but some elements are hard to read or use: especially its home-page wheelbased launch tool.

Some smartphones suffer from too many features, but Samsung's done a good job of making the strongest features the easiest to access. You can almost forgive the feeble battery...