This is a simple chord style keypad that I made up a few years ago. It is loosely based on the Microwriter – an early UK designed portable keypad / notewriter.
The five main keys are located under the fingertips and thumb of the right hand, plus an additional shift key that can be held down with the thumb. This combination allows up to 64 key combinations – which is enough for simple ascii, alphas and numerals.
However, this time the application is not for text entry, but to allow very rapid access to menu items, tools and colour options for a CAD program – without having to break concentration and use the keyboard.
Project info at Ken’s SustainableSuburbia blog.