The new user interfaces …
As the Palm and WinCE PDAs have gained popularity, so have the new user interfaces – or more specifically the new data entry techniques. Users of these devices now use “virtual pens” to “write” on the screens of their PDAs, and there are several different solutions evolving. There is the Palm Graffiti solution and the WinCE solution, like that in the Compaq iPaq.

In my observations and research I believe that these “stroke” or “gesture” based solutions are going to evolve and grow in popularity. I am working on such a solution now for my wearable computer business. This library of code is one that provides these types of features to Linux and some specific applications.

LibStroke 0.5 (Default). Stroke and gesture recognition library [freshmeat.net]