First off, the Romans and Greeks might roll their eyes at the idea that Walter Hunt invented the safety pin in 1849. They were, after all, using brooches and the like way before him. But Hunt created a pin with a coiled end (the twisted loop at the end of the pin) that provides a springing mechanism. He added a "clasp or catch" in which the point of the pin would be safe from tender fingers, when secured [source: U.S. Patent Office].
But for Hunt, ingenuity alone wasn't going to cut it. The safety pin was one of many nearly tragic business decisions in his life. By most accounts, Hunt seemed to have a knack for inventing a really cool product and immediately selling it, with no thought to the larger economy that could spring forth from his design.
Chief among those? The sewing machine. Yes, Mr. Hunt was the first to actually invent some of the significant parts of the machine, including a curved needle and shuttle. In 1833, Hunt created his prototype in wood, which didn't work so well. So Hunt sold the idea; the company that bought it made the machine in metal and put the machine on public display.
However, when two businessmen (Elias Howe and Isaac Singer) fought to control the patent of the sewing machine in the 1850s, Hunt was brought back in. Singer -- trying to discredit the patents Howe had filed -- had Hunt attempt to claim a backdated patent on his 1833 machine. Unfortunately, while the judge acknowledged Hunt as the inventor, the statute of limitations didn't allow for a patent so far out. Howe kept the patents, and later even teamed with Singer -- without a penny to be paid to Hunt.
Stymied again! But Hunt seemed to still take serious joy in the act of invention. He created -- among many other things -- a foot-pedal alarm to warn those in the way of streetcars, a knife-sharpener, an ice-plow for ships and an "antipodean" walking device. (that is, suction-cup shoes that allowed a "human fly" or other circus act to walk on the ceiling or walls).
So the next time you see Spider-Man scaling a building, perhaps you should be less impressed with the superhero and more grateful for Walter Hunt. Not only did he provide Spidey a neat trick, but he also gave our costumed friend a neat way to pin his spandex suit together without getting pricked.