Verbatim's Portable Hard Drive Executive is a 2.5in disk that can store 500GB of files and plugs into a USB socket using the supplied cable.

Unlike some portable hard disks, it can draw sufficient operating power from the older USB1 sockets too, although you may find it slower to copy files over such connections.

The disk is small enough to fit in your pocket and comes with a soft, padded case to protect against minor knocks. However, there is no space for the connecting lead inside this case.

The Executive comes with two pieces of software to help make the most of the disk: Nero's Back It Up 4 Essentials for simple backups, and Verbatim's own synchronisation tool that keeps documents, emails and a calendar up to date when working on more than one PC.

This information can also be encrypted in case it is lost or stolen. No manual, printed or PDF, was provided for the Nero software but it was fairly self-explanatory in use.

The disk also contains a program that claims to speed up data transfer over USB but our test showed no difference.

If you need to carry this much data around regularly then the Verbatim Executive is capable enough, if a little pricey.

But if all you need is extra capacity at home, products based on the larger 3.5in disks are better value.