The first portable hard drives for phones are coming onto the market, promising a "multimedia revolution".

Seagate launched its Digital Audio Video Experience (Dave) range of mobile hard drives yesterday, which consist of a 1cm thick credit card sized unit storing 10GB to 20GB of storage and communicating with phones via Bluetooth.

The devices have a range of around 30ft and battery life of 14 days standby or 10 hours use. No pricing details have yet been released.

"Mobile telephony is undergoing a multimedia revolution, and the Dave mobile content platform will provide even more fuel for the growth of new music and video services over mobile networks," said Patrick King, senior vice president and general manager of Seagate's consumer electronics business unit.

"Products using Dave will enable digital content for business or entertainment to be stored, moved and connected in ways never before possible."

But Seagate has been beaten to the punch on the technology by Agere Systems with a similar device, the BlueOnyx, that can communicate via Bluetooth or Wi-Fi and can store up to 40GB.

Models are also available with USB and SD card ports, and costs range from £50 to £130.

"We wanted to create a highly mobile device that solves a lot of the connectivity issues consumers have while giving them all the storage they want at an affordable price," said Ruediger Stroh, general manager of Agere's storage division.

"The capability will finally make the PC just another consumer device instead of the centre of the digital universe."