You can make garden spheres out of recycled bowling balls. They don't blow away in the wind, and they won't shatter into a million pieces if they get knocked off their stand. You can paint them or glue things to them. If you live in an area that gets freezing temperatures over the winter, you will want to bring your ball inside for the winter. An unheated storage shed is fine. Bowling balls are made up of different materials and some will shatter when exposed to water and freezing temperatures.
Complete instructions as well as more examples can be found on my website. http://www.gardensandcrafts.com/bbart.html