We inherited 1/2 a swing set from our neighbors. Last weekend, I turned it from this:
Alright, this isn't at all electronics or programming related, but it is still "hacking" in a form. The local hardware store doesn't stock parts for this purpose, they only sell "playground kits". It's mix and match, but they assume that you are buying a complete swingset, so they package some important parts in the big expensive kits, and don't sell them "loose". So I was on my own. At least they sold the actual swings separately, but I did have to make a return trip when I realized they did not come with hooks to mount the swing chains to the frame.