Digital Blackboard

If there were, instead of a slate blackboard, a similarly shaped sheet of E-Ink or Gyricon (go to e-ink and Xerox PARC respectivly for more info on these), a teacher could write on it via a touch sensitive tablet inbedded in their desk. This would allow for several things. One, the teacher could look at the students while writing, something I've noticed to be a real disadvantage to standard black and dry-erase boards. Two, it would allow for several input methods. A teacher could write with a stylus, or type, or paste images or even videos onto the display.

The most beneficial feature, however, would be the ability to store and retrieve data. If a classroom had an english class first period, a social studies class second period and the same english class third period, data such as the homework assignments and notes could be stored from first period, or even written years earlier, and retrieved for third period, while the board would be available to the social studies teacher. It would also be much easier to make compelling presentations to the class, including images along with lectures, and even videos or sound bites.