One I didn't know existed but have often thought would be a good idea:
CONTACT: Leave me a Houston or Texas media news tip | COMMENT: Click to leave your thoughts on this post hereTHE FLASH-DRIVE FUEL GAUGE You gotta love those U.S.B. flash drives. They’re cheap, shiny and tiny, and they offer a practically perfect way to transport computer files.
On the other hand, you gotta hate it when you plug in a flash drive to receive a file you need — and discover that the darned thing doesn’t have enough free space.
That’s the beauty of Lexar’s Mercury flash drive, whose case has a “fuel gauge” — a bar graph that tells you, without even plugging the thing in, how full it is. Thanks to a technology called E-Ink, this graph is always on and stays visible indefinitely, without requiring any power whatsoever.