My favorite playground item was always the Merry-Go-Round, which I thought must have been called something else, since it is not the kind with the horses, and found, thanks to 1000 Awesome Things (#980 Old, Dangerous Playground Equipment) that it can also be called "The Big Spinner". Somehow children were always getting trapped and mangled under its giant spinning wheel. I noticed as a child that these were usually children who decided they were going to take over the ride and run the show rather than playing as a group and/or taking turns being in charge, hence karma sucks their tiny dictatorship under the wheel of doom.
However, Dr. Nick Laslowicz, Chief Engineer at the Institute For Centrifugal Research in Florida has researched the brains interaction with the effects of centrifugal force (perhaps why kids enjoy the old merry-go-round of doom so much). Some of these rides look pretty amazing, but also, scary as hell:
(The Centrifuge Brain Project from Till Nowak on Vimeo.)
For now I think I'll stick to the monkey bars because I can handle a few blisters, or even a dislocated shoulder from an ill timed Cherry Drop.