Here’s a simple garden art project, that is wonderfully mindless. Use a strong glue to attach your surplus pennies to a thrift store bowling ball. It would be a great project to do with your kids on a rainy day. For the glue, my favorite is made by Amazing Goop, and I use the Home and Garden or Marine formula, because they are UV resistant as well as waterproof.
This is an idea that has been around for ages. I certainly didn’t think it up. I put my penny bowling ball by our front door after our recent move. So many visitors comment on how much they like it. I like it because it requires zippo maintenance. Although, during the move, it rolled out of my car onto the driveway (thank goodness, it didn’t damage the brand new paving), and three pennies fell off. Not bad. And gluing them back on went lickety-split.