The tire swing seemed like a good idea and I remember spending an awful lot of time down there - but unfortunately for us physics was not on our side. After a big push the tire would swing back and forth a couple times but eventually would circle back - right towards the trunk - slamming us against it. I distinctly remember putting my feet out - an effort to avoid a collision but it would only violently cause us to spin out of control. Oh those were the days.
Anyway, I installed a swing in our kitchen/hallway and the babies love it. It reminded me of those days - except that I try not to let the babies hit any walls or trees.