Loose change is generally a nuisance -especially the brown shrapnel kind.
Today’s invention is to create coins which each contain a bar magnet. This would allow all coins automatically to align themselves into a convenient column within someone’s pocket. No more rattling during presentations and, when you need to spend some change, just flip the required coins off the top of the stack.
If you wanted to go one step further, you could have slightly dished coins so that these could be arranged, partly overlapping each other, in the form of a bracelet or necklace.