Build an RC Catamaran

Nice build, the author took a plastic shoe box, some PVC pipe, 2 pool noodles, and make a propeller/steering system (oh and the motor/controller from an old RC car) to make a slick boat.  Figure under $20 in parts (between dollar store and home depot).

http://www.instructables.com/id/Build-an-RC-Catamaran/