How would I...?

I want to match a pattern drawn by the mouse motion to a symbol, such as a letter, such that, if the user were to, for example, trace the letter 'a' with the mouse, it would recognize that the letter "a" was drawn. Anyone have any idea how I could do this?

My jumping off point is capturing the points along the path of the mouse and comparing them to points in the stored patterns, but I'm not sure how to do the comparison. I can't come up with a way that will ensure, no matter the speed of the mouse motion, that it captures the same points in the pattern to make a decent comparison. So, then I was thinking of storing each point with information about it's position relative to the points immediately before and after it.