What is it? A portable hard disk drive.
What does it do? Like the internal hard disk in your PC, it stores data. Lots of it - the smallest model is no bigger than a Palm Pilot, weighs an anorexic 230g but boasts a Tardis-like 20GB capacity. That's equivalent to 14,000 floppy disks. So you can back up your entire system and put it in your pocket, or carry the heftiest digital audio/video files around with you without ever again having to resort to fiddly compression software.
What's the competition?
Iomega - the company that brought you the Zip and Jaz drives - has had the portable storage market sewn up for years, and the HDD continues the trend. Recordable DVDs have the advantage of interchangeable discs, but they are slower in operation and offer only half the capacity. When it comes to bytes per buck, there's no comparison.
Where can I get it?
The 20GB version is available now, directly from Iomega, for about pounds 180. Versions with 40GB, 80GB and even a whopping 120GB capacities will follow shortly.