The company that first invented the USB Flash memory drive in 1999 has unveiled what it claims is the world's smallest USB Flash disk with built-in security.

Weighing 13g and measuring 5.5 x 13.5 x 53mm, the OnlyDisk U220 from Netac Technology features built-in encryption technology which automatically shows the device as two removable drives on My Computer, one normal and one secure.

Users can allocate any amount of capacity to either of the drives, or make the disk all secure without any public zone.

The secure drive allows owners to set a "retry limit" on the password, locking the data if the wrong password is entered too many times. After this the drive must be wiped with the unlock utility to free the space.

The OnlyDrive U220 is compatible with Windows 98/ME/2000/XP/Server 2003, Mac OS9.x/X and Linux 2.4x, and uses USB2.0 that can transfer data at up to 9.5Mbps.

The drive also supports USB1.1 and provides faster speed (1.2Mbps) than normal USB1.1 disks. The U220 supports Bios boot up as USB-ZIP and USB-HDD.

The drives are priced at £23.99, £29.99 and £49.99 for the 512MB, 1GB and 2GB versions respectively (inc VAT).