Dish TV makes a system that is suitable for a mobile home and is made to travel. That would make an ideal experimental tool. You could combine a traveling vacation with a FET experiment. I know there's an iPhone application that will tell you where to point your dish antenna. You could then do a little trigonometry and easily prove that the earth is indeed round. Probably you could just use the iPhone app, stay at home, and use hypothetical positions to prove the same thing in the comfort of your own home.