If there is one complaint I have about every boomerang competition I go to, it's that there simply aren't enough hot dogs. Apparently boomerang enthusiast Paul Sprague and I don't frequent the same contests, because when he goes boomeranging (yep, that's a word), he brings along his self-designed BoomChef solar-powered grill, built intentionally for grilling up hot dogs at boomerang competitions. When he says solar powered, he means it—the thing is literally a glass box that catches sunlight bounced off a reflective Mylar panel.
While Paul claims his design is capable of cooking just about anything you'd want to throw on a grill, your body will probably thank you if you stick to pre-cooked foods like the hot dogs it was designed to heat up. On the sunniest of days you can expect a BoomChef to get up to about 230 degrees Fahrenheit after a few hours in the sun, which will actually cook food, but you'll be waiting awhile (long enough to go throw some boomerangs or something). Between the sweet technical diagram and the production notes on the official site, you can probably try out your own "cheap to build, free to operate" BoomChef grill next weekend. [BoomChef Grill via Neatorama]