Livescribe has created an igneous notational system comprised of the "Pulse Smartpen" and their proprietary dot paper. The pen features an infrared camera, OLED display, microphone, speaker, and USB connector. The paper contains microdots in order to track the pen's infrared camera.
What does all this techno babble mean? As you write down your notes during a lecture, the pen and paper track what you are writing and and ties in the audio of the lecturer to the moment in time that you made a particular note. Later on when you are reviewing your notes, you click on a particular word or phrase, and the audio from that exact time that you made your note is played back through the built in speaker or via headphones.