People have mentioned it's similar to the "Boogie Board" LCD tablet (shown here on ThinkGeek:
http://www.thinkgeek.com/geek-kids/3-7-years/e330/) but the BB doesn't actually save anything. (Think an etch-a-sketch with a stylus instead of knobs.)
If it can import pdfs (looks like they want v.1.5 to deal with file input, and v.1.0 is just file creation) and has an all-day battery life, $99 is totally in "buy out of curiosity" range. Heck, I thought the $199 Asus EeeNote was in "buy out of curiosity range."