This is such a great idea. Take one old satellite dish and a pile of AOL CDs or whatever old software you have filling your drawers. Bolt the CDs to the mesh of the dish. Voila: a solar stove capable of 800 degrees F.
These pictures show a temperature of 400 degrees. This is adequate for my uses. In an earlier experiment I had CD's covering every available square inch of the surface of the dish. It produced over 800 degrees. More that I needed for cooking. Do not try to retrieve anything from the focal area without a leather glove on. If that didn't come to mind right away then you maybe shouldn't try this.
Learn how at Instructables.