Pencil like drawing

I'm wondering how easy it would be to make a vector-based pencil like tool?
I'm in need of something very similar to that used in the MSOffice drawing stuff. If you right-click on something you've drawn you can edit all the points - but the neat thing is it's transformed into bezier curves. I'm assuming this would save gobs of memory, and was wondering how to do this? Or does it require such high end math I may as well forget it unless I have lots of learning time on my hands?