On April 10 we celebrate the safety pin, patented on this day in 1849 by an inventor named Walter Hunt. Hunt is known for a number of other inventions, too, including an innovative lockstitch sewing machine, an icebreaking attachment for boats, and a nail-making machine, to cite just a few examples. Like the paperclip, the safety pin is basically a bent piece of wire, but its simplicity belies its utility. It has spared many a finger from unwanted holes while keeping clothing together that really wants to be apart.
Image credit: By Haragayato [<a href="http://www.gnu.org/copyleft/fdl.html">GFDL</a> or <a href="http://creativecommons.org/licenses/by-sa/3.0/">CC-BY-SA-3.0</a>], <a href="https://commons.wikimedia.org/wiki/File:Safety_Pin.jpg">via Wikimedia Commons</a>