The AirStash behaves much like a USB flash drive with a removable SD card for its storage but has a wireless connection for sharing data with one of Apple’s devices, even when not plugged into a computer. So you can store documents (especially media) away from the limited storage of the iPhone or iPod itself without losing access.
This is huge. Huge I say. Why? Because if the iTablet/iSlate/iGuide thingy from Apple ever arrives, then this little beauty could give you all the extra storage you need — and keep a sleek, paper-thin design.