WD Elements Portable simply affordable, easily portable
The WD Elements Portable is a simple, high quality portable drive that is light and easy to carry - simply plug it in to any USB port and start saving your photos, music, video, and files. Designed with the same commitment to quality that made WD external drives the number one drives in the world, just plug it into a USB port and you are ready to go perfect for data storage and transfer when on the go.
USB powered with a compact design
Powered directly through the USB cable the WD Elements Portable require no power adapter, adding to the ease with which they can be transported and meaning your data transfer is a quick and hassle-free experience. Should your computer be one of the few which limits power to the USB port, an optional cable is available (sold separately
This drive is very well reviewed.
There is another WD 500gb available for £44.99, but you have to plug it into a supply.