Datel made big waves with their hard-drive for the Sony PSP. Now they offer a portable hard-drive for the Microsoft Xbox 360.
The Datel Xbox 360 4GB Portable Hard Drive connects via USB 2.0 to the Microsoft Xbox 360. It features a green glowing power Xbox 360 button on the case.
The original 20GB Xbox 360 Hard-drive can also be called portable. Additionally any USB external hard-drive actually can be connected to the Xbox 360. See this report on LLamma explaining the details. The Datel Xbox 360 hard-drive is for those who want a small portable drive with Xbox looks. The drive is available for pre-order on Dark Planets for £74.99 (~$133).