Box2D AS3 framework provides you with everything you need to create 2D type of platform, car, RPG games and other. For small project or tutorial like this one it’s fine to use quick and dirty direct references to graphics and b2Body like I did, but for bigger projects you should wrap up all functionality and references into classes to cut down the amount of code you have to write since creating b2Body or b2joint or other in Box2D can require a lot of line of code. This is what I did for the MightyDog game where all the Box2D elements are created dynamically by xml using a well structured set of classes.

I hope you will have as much fun as I do have when I work with Box2D!