The Twiddler3 is a one-handed keyboard and mouse hybrid that relies on chorded movements akin to the ones made when you play a guitar. Rather than just being a miniature version of a regular keyboard, the Twiddler3 is actually designed to feel more like a joystick. It offers full access to a keyboard and mouse in one hand. The device has a fat charge and doesn't need to be recharged very often.
This one-handed keyboard-mouse hybrid has four special keys -- num, alt, ctrl and shift -- which are controlled by the user's thumb. The other four fingers control three mouse buttons and 12 other buttons used to type.
The Twiddler3 is certainly a device that poses a steep learning curve, but the ability to get your work done while still having one free hand is certainly alluring.