Seagate's FreeAgent Go Offers World's First Bus-Powered 640GB 2.5-Inch Portable HDD

Seagate's FreeAgent Go line of hard drives is home of the first 640-gigabyte portable in the beloved USB bus-powered 2.5-inch form factor.

This means that you get a ton of portable storage space, and you still don't need an AC adapter. You just plug the drive into a USB 2.0 port and proceed with your business. Simple, easy, nice. Pricing and availability is still up in the air for now, but we'll keep our eyes peeled. [Seagate]