The Wacom Inkling Digital Sketch Pen (affiliate link) is a tool that lets you draw with a regular pen after which a sketch can be transferred to Photoshop or Illustrator for further editing. No, it does more than a regular scanner. First of all, it allows you to draw in layers and preserve them in the editing software. Secondly, the hardware is so small that you can take it any where you want.
My box arrived yesterday in the mail and the experience confirms what I have seen so far in the promotion video (my sketching skills have some way to go though). The product comes in a box the size of a regular pencil case. The pen and the receiver fit in nicely. Clip the receiver at the top of the page, and start sketching. It is as simple as that. One button opens a new file/page, another button adds another layer. The software is easy to install and works great.
The only drawback for me is that sketching has to happen with a ball point. I prefer a soft tip pen, or best of all a thick pencil to draw. There might be technical reasons why Wacom stuck to a ballpoint for sketching, but hopefully they will release a pencil-based scanner in the near future.