Idea
One of the problems with mobile devices today (PDAs, Cell Phones, Tablet PCs, etc.) is that there is no quick, reliable form of input. Keyboards are far too bulky to carry around, and they have to be laid on something to type. Currently there is hardly a viable replacement for the keyboard. Voice input is sketchy, and requires a ton of resources. Handwriting recognition is getting better, however it is much slower than keyboard input.
Here is an idea of a device alternative to a keyboard. This device would have two eight-way directional pads (similar to a game controller, see Figure 1). Additionally it would have one trigger button that would act as a “shift” button. Ideally in a shipping device the two directional pads would be built right into a device, along with the shift trigger.
Figure 1.
The input device works like this: each combination of button directions (i.e. left pad pressed to North & right pad pressed to East) corresponds to a letter, number, or other input normally done with the keyboard. By having two 8 directional pads, we have a total of 8 x 8, or 64 different inputs. This is plenty to cover the alphabet (26 keys), the numbers (10 keys), symbols (11 keys), function keys like enter, tab, space, backspace, delete, esc (6 keys), and 8 direction keys (8 keys), plus 3 programmable inputs. With the addition of the shift trigger, all shifted values also are available (Capitals, more symbols). Input with this device could potentially be as quick as using a keyboard (with some practice).