Jacob Wobbrock, who created EdgeWrite, also published on gesture recognition with the $1 Unistroke Recognizer [1], which started the $ family of recognizers. If you think there's some sort of gesture-based writing scheme that would do better, you can use the gesture recognizer and focus directly on how to design your gestures instead of having to implement recognition yourself.

There's a pretty cool demo with a Javascript implementation in a couple hundred lines here: http://depts.washington.edu/madlab/proj/dollar/index.html

[1] http://faculty.washington.edu/wobbrock/pubs/uist-07.01.pdf