To make a duct tape sled, you'll need: a cardboard box, 3-4 rolls of duct tape, and scissors and/or an X-Acto knife. (I got my duct tape at the dollar store for $1.25 per roll.)
Start by cutting one side out of a box. We used a 5 cube moving box.
Then, fold one end of the box over, and cut a handle through the two layers. The extra layer of cardboard will make the handle stronger.
Finish by covering the entire sled with duct tape. Make sure to seal all the edges with duct tape, and overlap the tape to ensure that the cardboard will stay dry. You are also going to want to use the tape vertically as much as possible to increase the speed of the sled.
Gina (aka East Coast Mommy)