I know that pen-and-tablet input devices for computers have been around for a long time. I even had one maybe about ten years ago that I never really used a lot. But here's a cool product that I've never seen before - a digital pen. Actually, there are two of them: the Mobile Digital Scribe and the ZPen.
the Mobile Digital Scribe by IOGEAR
Basically there are two parts to the system: the pen itself and a receiver that you clip to the top of the sheet you are writing on. You don't need any special paper or tablet. As you write, the receiver captures your handwriting and stores it. (The exact mechanism for the capture is not made clear by the product web sites. Something optical, maybe?) When you are done, you simply plug the receiver into the USB port of your computer and you can dump the memory into a file.
For an amusing review of these digital pens, check out David Pogue's short film on the New York Times video site.