Indiana teenager Eric Jacqumain has built something he calls the R5800 Solar Death Ray. It is a common satellite dish with 5800 small mirrors attached to it.
The ray generates enough power to melt steel, vaporize aluminum, boil concrete, turn dirt into lava, and obliterate any organic material in an instant. Take a look:
Could this be used as a Weapon--Death Star or Austin Powers? You choose.