Alternative Text Input Methods?

A reader asks: "I've been tentatively researching existing solutions to enter text without a full (QWERTY) keyboard, and besides touchpads, morse code, and the system used in mobile phones (added with dictionary-powered predictive methods) and some wild gesture-based ideas I've come with the following systems: chording, as exemplified in some of the keyboards in this gallery, and Thumbscript (which is patented). Does anybody know any other good methods to enter text on a limited keypad? This issue is likely to become more important as new, smaller devices of all types enter the market." Interesting question. Devices that are already in the market (and those soon to hit the market) which are designed to be portable in size (but not in functionality), this will be a huge issue. Try editing song titles on today's portable MP3 player or writing a paper on your Palm. It's doable but not very pleasant. Such alternative methods would be a welcome addition to such devices.