Sure, there are really slick tablets out there meant for artists and graphic designers, but writing on a tablet is still not the same as writing on paper. That's why devices like this unfortunately-named WowPen keep popping up; they want to give people the ability to turn their pen-and-paper drawings into digital masterpieces.
Unfortunately, these things are currently better suited for writing and crude drawings than artistic masterpieces (unless crude drawings are your masterpieces, of course), so you're probably still better off just getting used to using a tablet for now. This one involves sticking a USB device to the top of your pad of paper; it senses what you're drawing, and you can hit a button to switch between drawing and using it as a mouse. Could be useful, depending on what you need it for.