The first video in the Physics Patchalong series takes you through creating a falling object and interacting with it in a couple different ways. Follow along as Rob Ramirez goes through the creation of a fully functional physics simulation.
Part 2: http://youtu.be/sRhQxfEvOIQ
Part 3: http://youtu.be/bArs9nnvGCw
Get more information on Jitter Physics: http://cycling74.com/physics/