Only application I've used this for so far is a technique for defining and recognizing gestures. They're called "flash gestures" (or that's what the page where I read about them called them) where you find the closest of 8 directions to the gesture direction and encode each gesture as a sequence of digits 1-8 corresponding to these closest directions, then use the Levenshtein distance algorithm to find the closest matching pattern.

EDIT: Found the reference I used to implement this.

https://books.google.com/books?id=_1rSBQAAQBAJ&pg=PA85&lpg=P...