Wandering around the neighborhood Shepard's Bush, I came across these fun cube sculptures. If you get enough of you friends to join in, you can get them spinning quite fast. Some of the more nimble climbers can shimmy up the structure for a lesson in g-forces.
It just seemed dangerously fun. If I didn't have massively expensive equipment in hand, I would have tried my hand at getting my teeth knocked out. Their smiles let me know they are wiser and more graceful than I; they seem to have all their teeth.