Thad sent photos from the Construction Derby which is a charity gravity race in Oklahoma City. You can view all the photos here.

The 1st annual Gravity Shoot-Out began with a shaky start. It was raining at start time, we didn't know if it was still on or not and the event's organizer couldn't make it. Despite the uncertainty of the weather and what to do, it turned out to be a great time with very little rain. We raced all morning, took a break to eat and raced some more. Stretched plastic kiddie cars, bikes, a couple of modified little red wagons and scratch built racers made up the 10 or so vehicles that participated. There was probably twice that many people in attendance.
I don't think there were any official results but Thad's red wagon racer, Wes's coffin car and Steve's bike were probably the top 3.

Lots of photos here.

Pop some pop corn, sit back and watch all the exciting action (2 videos) here...

2 wheels (gravity bike) are welcome also!