QuadEntry in Clutter
QuadEntry is an input method for cursor keys or four-way pads based on interactive navigation of a quadtree.
For normal text entry you need three presses, for instance entering an 'a' is achieved by pressing the keys up, left, up. This would take you to the upper quadrant, then to the left quadrant of the upper quadrant and finally select the upper pad of that quadrant.
I originally came up with the concept for QuadEntry when I was playing experimenting with and exercising cairo back in 2004. I've resurrected the QuadEntry when I started digging into Clutter, which is one of the nifty projects coming out of OpenedHand, my new employer. Since being able to use the QuadEntry as a virtual keyboard for clutter depends on a more capable event handling and filtering system in Clutter I'll let the actual publishing of the sources wait until it builds without some hacky changes to Clutter itself.