What is it? Freerunning. The goal is to move from one point to another as quickly and efficiently as possible. In my terms . . . really cool movements that scare a mother half to death.
Here are some pictures of Thomas doing Parkour earlier this month. I wish these photos did him justice. He has been known to run up the side of a building, flip off of a roof, and jump over fences quite swiftly and smoothly.