I think smartphone users, particularly those on Android, need to give Voice Recognition a serious look. It's one of those technologies that has quietly gotten better and better in the background even after a lot of people wrote it off.

I use Voice Text (http://androinica.com/2009/07/29/voice-text-turns-your-speec...) and couldn't be happier (Yes there are still errors but you can dictate a full paragraph and then just fix the 3 or 4 wrong words)

I agree about voice recognition getting much better.

My business partner's wife is visually impaired, and he wired up his house with a whole-house stereo, mics in each room, and a speech recognition daemon, attached to each mic. He then wrote a huge pile of scripts for things his wife might need to do.

Now she can ask the house about the weather, control the thermostat, check the status of the garage doors and locks, turn on/off lights, open/close blinds, make phone calls, change the music, and a few other things I can't remember.

It's all a tad too expensive to be a commodity, but overall I believe it cost him something in the $40k neighborhood, which is incredibly reasonable for something that makes his wife far more autonomous.

A business opportunity - an efficient input device/method for mobile devices?

I often take photos of textual signs for use later. Take it to the next level: OCR text from the built-in cameras. A friend suggested OCR from live video was even possible (on an iPhone!) My vision was being able to enter text by scribbling something on a napkin, and OCR'ing the text in.

Another cool method is Dan Bricklin's Note Taker (http://news.ycombinator.com/item?id=997264) Just need to add OCR.

Now, my experiments with OCR algorithms didn't work too well. Apparently the training data is the most important component.

Handwriting recognition is also possible, but still images lack the very useful stroke info.