Hanwah Japan’s new Duo digital pen allows you to turn a standard 15.4-Inch LCD laptop into a tablet PC through infrared and ultrasonic magic.
In order for the system to work, a receiver must be placed on top of the screen to capture pen movements, but the result is a decent-sized screen for your doodles. That sounds like a pretty handy device for around $US104. [Hanwha via Akihabara News]