There is another honorable estimation, rather a conceptual USB which glows according to the file type. I have seen the same thing at iTunes, when i plug-in my iPod it usually shows different colors for different files types. The same idea has been grabbed and implemented on a USB drive.
Actually according to the pictures the USB glows continuously even when not plugged in so how does it get enough power ? Where does the memory reside ? This usb is manufactured with glass rather than a plastic body, i guess the secret might reside in its design.