Jeff wants to know more about Sony Digital Paper. Leo says it uses e-ink, and while it has extremely long battery life, it has traditionally had a problem with latency. Sony has a video that shows it keeping up with handwriting, so maybe they've overcome the latency issues. At $800, though, it's a bit pricey. But if it does what Jeff needs, being a digital yellow pad, then perhaps it'll be worth it.
Jeff should check out this YouTube review.