First of all, it's not a tin foil hat. It's a tin foil safety tuque. Second of all, it's finally been scientifically proven that it guards your brain from a wireless modem's signals. The jury's still out on mind control.
Actually, making a little Faraday cage for your head is a fun experiment, although I'm not sure about the ultimate benefits. But I'm sure I'll find out when we're all subjugated by the new world order, with only our tuque-headed brethren left to mount a resistance. [YouTube via Make]