When I was a kid (okay, recently too), I loved using lemon juice to write secret notes in disappearing ink. New research being done by the Palo Alto Research Center (PARC), a Xerox research facility, has found a way to make disappearing ink for printers, too. Documents printed on its reusable paper can be erased and written over by printers using a new ultraviolet light technology. Recycling made easy! While the technology won't be commercially available for a few more years, it's not going to be exorbitantly priced, and it will actually help you save money because you'll use less paper, and because it takes less energy to print a document using this technology than current printer technologies (and far less energy than recycling). Win-win!

Read more on this amazing new technology on the Green Tech Blog.