Pads of the paper with the special pattern will be sold by Livescribe. Users will also be able to print the pattern on regular, blank sheets of paper using certain high-quality printers.

Marggraff says that the dot-positioning technology, which he read about in a magazine, was partly what inspired his endeavors in paper-based computing. Before the Livescribe smartpen, he worked on the Fly Pentop Computer, a product for children developed from earlier applications of the technology.

In addition to the microdot pattern, the Livescribe smartpen makes use of other technologies, including a 3-D audio recording system. This technology, Marggraff says, is designed to make the pen's paper-replay function more useful in less than ideal recording conditions. If a student using the smartpen gets stuck in the back of a lecture hall, for example, most recordings would risk being too low-quality to be useful. The pen, however, uses two microphones to record the sound the way the user would have heard it originally: the two microphones help the listener sort different sounds, much as information from two ears helps people identify the source of a sound.

Rodney Brooks, director of the computer-science and artificial-intelligence laboratory at MIT, who has been an advisor to the product, says that connecting writing and computation in the smartpen is "a real step forward." While Brooks notes that it's unfortunate that a user must have special paper in addition to a special pen, he is still very enthusiastic about the technology. "If a magic wand could be waved and you didn't require [special paper], that would be wonderful, but these are pretty big steps even without that," he says.

Other companies have previously made products using the dot-positioning technology. Logitech, for example, licensed the microdot pattern from Anoto to build a digital pen called io. Mark Anderson, director of business development at Logitech, says that the io employs the dot technology to allow users to take notes and view them as typewritten text on a PC, and other similar applications. However, at this time, Anderson says that the io does not have multimedia functions.

Beyond the capabilities that the Livescribe smartpen already has, the company is releasing tools that developers can use to build their own applications for the pen. Marggraff hopes that the pen will become a new computing platform for consumers, replacing some existing mobile products.

Brooks says that he can imagine the pen taking on that role. "People do change their platforms," he says.

The smartpen is planned for release in January, when more product details will be available.