Good times. We would play with doctored wiffle ball bats and tennis balls. We all had our own bats that we loaded with whatever. we'd chop the ends off the bat and stuff it with whatever we could find. My bat was stuffed with newspaper and a couple tennis balls that were cut up into little pieces. The tops were then taped back on with duct tape or electrical tape. I preffered using black electrical tape. We'd reinforce the bat by wrapping the handle with so much tape the plastic wouldn't be able to bend at all. We eventually had to devise a standard for how bats could be doctored. This was spurred by one kid coming with a new bat that he loaded with a large block of wood. It was as close as you could come without whipping out a Louisville Slugger.
But we would play games of whiffle ball if we had enough people. If there weren't enought we'd play home run derby. I remember one summer one kid actually kept home run stats for us in a beatup Mead notebook. I'd love to see that now.