Originally Posted by OHBH
Check your local craigslist page, teachers looking for old tennis balls to be put on desks and chairs are continually posting in the "wanted" section.
You can also halve them and use them for "targets" for almost anything. You can put them out on the tennis court and serve at them... shoot them with a gun and zero in your optics... whatever.
"In the 1980's two men dominated--sometimes each other, most of the time everyone else."