Tiny USB hard drives are good hardware. They've revolutionized data storage and interface. Even the New York Times has caught on to USB hard drives for carrying files around. But there's a lot more the USB hard drive interface can do.
The key thing is you can plug a tiny device into your computer and copy files off of it with no special software. So my MP3 players just mount and let me drag my MP3s on. And both my real camera and my keychain camera let me download photos just by plugging it in. So simple, and I don't have to use some horrible software with a proprietary protocol.
Some of these devices are even bootable; you could take your whole Linux environment with you. In the guts of these devices somewhere must be a $3 part, a USB controller that speaks the hard drive protocol. A good thing.