Living in the Michigan cold has one advantage that is not often found elsewhere, water freezes outside. So I have decided to build and back yard hockey rink for my son next year. It will not be anything massive but just something small enough that he can use to work on skating and stick work. I found a very cool website that shows no limits on how professional these things can get. Kind of makes me wonder what the zoning dept. says about them.
A guy in my hometown turned a section of his yard into mini-hockey rink in the winter and batting cage in the summer. I have seen other people put in putting greens, soccer goals, and of course swimming lap pools. However, I think the strangest (and possibly most dangerous) was some former co-workers of mine that built a freestyle ski jump in their back yard. The starting launch pad was on the roof of the back porch.
Did you ever have any back yard sports set up when you were going up? What about for your kids?