Erasable paper? Maybe it's easy enough to erase something you jotted down in pencil, but imagine being able to take entire sheaves of copy paper and being able to wipe the slate clean. Xerox wants you to be able to do just that:

This week, research labs at Xerox announced that their scientists have invented a way of printing to paper which only lasts for a day -- as in the paper will fade back to complete white within 24 hours, making them totally reusable. The actual technology is in the paper itself. Scientists said that they were able to create a paper that reacted to certain wavelengths of light, and by using these special wavelengths, images and text were printable on the paper.
Of course, one might ask what the point of paper that can never have permanent markings on it is. However, when you think about it, many office notes are used only once. A business meeting agenda, a memo on a desk, and many things like it. Things worth printing out for many to read, but not something that has any practical use days later. Quite interesting, really. It would require a different type of printer, of course, meaning one more huge piece of equipment in the office. But the concept is cool.