The four-ounce, $30USD, Boogie Board runs on a watch battery and mimics the feel of putting pen to paper. To erase, simply press a button. It is a 8.75 x 5.5 inch thin plastic slate that has the same functionality as the Magic Slate (it doesn’t store what you write) except that it uses LCD technology. However, the battery that powers the Boogie Board is not replaceable. Once it’s depleted, the board is useless. According to the Boogie Board site, that’s around 50,000 erase cycles.
I won’t tell you why I’ve been so interested in the Magic Slate, 18th Century PDA, or this gadget, but I’m sure you might be able to imagine some uses for them.