There's tons of videos out there on stuff like this. I'm really fascinated on the topic of fitness at the park because of affordable and accessible it is. In any case, here's another video that I thought was cool. Let me explain why:
http://www.youtube.com/watch?v=IMjFN-m2VOM&NR=1First, the explosive power and body control these guys have is incredible. That's just a given.
Second, the second guy in there does a move where he uses a pull-up to get on top of the bar, then push up on the bar. This is a huge crossfit move so it must be do-able, but I couldn't figure it out at ALL when I tried. Can anyone out there help me out?