I have heard that Gazebo(Simulator) is used extensively for the DARPA challenge, have you had much experience with it? Does it save you any time and how practical/applicable is the simulation compared to the real world?
I had the opportunity to build my own robot in it, the furthest I was able to go was getting 2D navigation working based on some libraries in ROS using a laser scanner. Unfortunately I can't upload that video since my computer was too slow, but I made another one.