Sweet pen, John! You'll never cease to amaze me with the materials you use for pens.
I think bowling balls have unlimited uses - other than bowling, that is. I went whitewater rafting on the Salmon River in Idaho when I was in grad school. The little town of Riggins has a special tradition for the Forth of July each year. There is a steel pipe embedded into the concrete boat launch pavement. They pack the pipe full of gunpowder, drop in a bowling ball, and touch it off to launch the ball over the mountainside across from the river.
This is cooler than you might first think - since the Salmon river is actually the 2nd deepest canyon in the USA. The Hell's River Canyon is the deepest (from mountain top to river), and the Grand Canyon is actually the 3rd deepest - but much wider and more famous.
I'm not sure if I could kick the topic more off course than that!