As well as providing the hardware for the Nike player, Rio has produced a new MP3 player itself, in the form of the Rio 600. This is a follow up to its market-leading 500 device (reviewed here, when the company name was Diamond), so it's interesting to compare what's different in the new model.

For a start, the Rio 600 is styled in a much more rounded case, nearly all plastic, so it's lighter, but probably less robust, too. There's a back-lit LCD display which shows track title, artist and volume settings. A control disk tilting any of four ways provides player control, with three separate buttons for menu navigation. A single socket in the top takes two separate plugs, one for the clip-on-the-ear headphones and the other for a USB connection.

The Rio 600 is claimed to run for 10 hours on a single AA alkaline battery. There's no power supply, but the unit draws power from its USB link to a PC or Mac when you're downloading music tracks. Replacing the cell involves removing the back cover, which is connected via a plug and socket with two rows of flimsy-looking pins - not ideal. Optional replacement back covers can hold more memory, too, so you can add another 32MB to the 32MB supplied. Early next year, a 340MB back, based on an IBM Microdrive (which we'll be reviewing soon), will be released.

Software has been a strong point of previous Rio players, though here it's the same as with the Nike player, but renamed Rio Audio Manager 3. Overall, then, the 600 is only a partial improvement over the 500.