Starting our list of inventions with a bang -- or a pop, at least -- is the toy balloon. Blow one up and bop it around or fill one with helium and watch it fly. You could make a strong case that balloons, at just a few cents apiece, provide the highest fun-to-cost ratio on the planet.
Although toy balloons have been made from latex since the early 19th century, the first toy balloons were made of something a little harder to stomach -- animal intestines. After cleaning them out and stretching them, they could be filled with air, just like the balloons you buy at the store. In fact, the Aztecs even created balloon shaped like animals this way as part of certain religious ceremonies [source: Merlin].
Thankfully, manipulating animal entrails is no longer a part of the balloon-making process. Instead, balloon molds are dipped into vats of pigmented latex and allowed to dry. Once the latex is pulled away from the mold, the balloon is ready to hit the shelves. Fortunately, balloons are extremely cheap to produce. Otherwise, balloon enthusiasts like Treb Heining wouldn't be able to create the massive spectacles seen at events like the Olympics and the Super Bowl. Heining certainly wouldn't have been able to coordinate the world's largest balloon launch for the United Way, where he released 1.4 million balloons at once [source: Seattle Times]. But whether you have a million balloons or just one, you're in for some fun.