Xerox has decided that, since people can't seem to stop printing things, and that wasted paper is environmentally unfriendly, they'd make a self-erasing paper product.
The paper contains specially coded molecules that create a print after being exposed to ultraviolet light emitted from a thin bar in a printer. The molecule readjusts itself within 24 hours to its original form to delete the print, or heat can readjust the molecule instantly.
Each page can be used up to 100 times provided you don't spill coffee on it, crumple it, or otherwise desecrate the paper in a way that would prevent from going through the printer again. Personally, I think this is brilliant, and a great way to save paper. Of course, I haven't heard a mention of cost, which is probably significantly higher than the paper's non-magical competition (regular damn paper). I just wish I had slipped a sheet of this in when my marriage certificate was being printed. You know, so I could be released from the chaffing bonds of this unholy matrimony.
UPDATE: Hmm, so it seems that this is old news, so I'm not sure what the hell this article was talking about. Oh well, hopefully you hadn't heard about it before (and that disappearing ink gag shit you used to spray on people as a kid doesn't count).
Xerox Spy Paper Will Self Destruct In 24 Hours [ohgizmo]