I first played Skittle-Launch at youth camp when I was 11. Its a blast to see your kids do this one. What you need: big bag of Skittles, a tape measurer (at least 30 ft long), clear tape, and at least 30 feet of space to work with.
Basically you give each of your kids a Skittle, tell them not to eat it, have them stick the Skittle up their nose one at a time, step up to the end of the tape measure at the end with the 0, and have them launch the Skittle out of their nose. The idea is to see how far they can launch it with their nose power.[Ed. Note: Needless to say, exercise care when sticking these in your nose. Don’t put them fully inside… just held in place, partially sticking out.]