Step 1: Collect Your Materials
1 Solar Light -- These can be bought from Wal*Mart and most home improvement stores. They're the kind that you stick in the ground. They charge during the day and shine a small light during the night. You can buy them in singles or in packs. If you are going to buy in bulk, try ebay, as they will be cheaper. If you are only buying one or two, ebay is not a good option because of the shipping costs.
1 Small (personal) Fan -- These can be found just about anywhere for less than a dollar. I happen to have an old one sitting around, so it was free for me. Ask your friends if they have an old hand-held fan that they don't use anymore before buying a new one.
You'll need something to construct the ducting. I used duct tape and a vacuum attachment, but in another step I'll offer a way to make ducting out of just duct tape.
You may also want a couple of switches and some spare wire, and possibly some weather striping, but it isn't necessary. As with many projects, make sure you have plenty of common sense before starting this project!
The only tools I used were a soldering iron, a pair of scissors, wire stripers, and duct tape.