Anyone who's been a student knows how hard it can be to scribble down everything someone else is saying. This problem is brilliantly solved by the Livescribe Pulse, a computerized pen that records as you write and digitally syncs the audio recording to the notes. Write or draw on specially patterned paper; then tap the pen on a word or sketch, and it will play back what was being said when you made those marks. The pen can also solve equations and define or translate words.

A. Camera
Seventy times a second, the pen photographs specially printed paper within a radius of seven millimeters, using a camera and an infrared diode behind the point to read a pattern of dots. The pen uses the photographic information to map its location against the complete pattern.