Sony has bulked up its skinny Micro Vault Tiny USB memory key family with a beefy 4GB model. The Flash drive is still thin enough to fit inside a computer's USB port.

We say the drive is 4GB, but Sony said it's pre-loading compression software onto each unit - Windows only, alas - that can increase the storage capacity threefold. How much extra space you get depends on what you store on the drive - different kinds of data compress to greater or lesser extents.

The 4GB Micro Vault Tiny is available now in a choice of five colours and packed in an equally colourful wrist-worn wallet.