Whiteboard sticker for your laptop
Actually, this just gave me a crazy idea... what if laptop manufacturers included something low powered like a boogie board device on the outside of the screen, which could write / save directly to some small internal storage of the laptop, and then the resulting notes could be accessible via the laptop when turned on?  Kind of like.. a poor man's tablet on the outside of a laptop?  I wonder the cost of that vs. touch screens / digital pens.