"I wanted to create a handheld electronic device to quickly measure the size of a metric or standard nut or bolt head," said an inventor, from Newport, Ark., "so I invented the DIGITAL WRENCH FINDER.

You've got a damaged bolt-maybe it's stripped, maybe it's bent-so you head to the hardware store for a replacement. There you are, surrounded by bolts, nuts, washers, and all sorts of small hardware.