The Hypershop has released a HyperDrive hard drive (http://www.hypershop.com/ProductDetails.asp?ProductCode=IPHD%2D000) designed specifically for the iPad. It’s an USB hard drive that can purportedly carry up to 750GB of HD 720p video and photos.
The HyperDrive can also be used to back up and view view memory cards without computers or external power. With it you can perform file and folder operations like copy, cut, paste, delete, rename, create new folder, sort file directory by name/date/type, format hard drive, erase card etc.
The HyperDrive lets you selectively copy single or multiple files/folders between memory card and internal hard drive. Pricing ranges from US$299 for a 120GB model to $399 for a 250GB version.