Build a soapbox car out of trash found in your neighborhood.
I am the owner of the Open Source Gallery, an alternative art space in the South Slope district of Brooklyn, NY. We host a Soap Box Camp for kids and a Soap Box Derby for kids and adults every August. All cars are built completely out of trash we find in the neighborhood. We organize a block party and, given the fact that our street has a nice incline, we race dozens of vehicles down the street. Judges evaluate the entries on criteria including engineering, design and SPEED! My car made it up to the top 3!