The problem with safety guidelines is that they make most playgrounds so uninteresting as to contribute to reduced physical activity.

Playgrounds don't look like they used to. Steep metal slides and wooden towers have given way to slow, plastic slides and carefully penned-in climbing contraptions.

And forget about seesaws -- they're a thing of the past.

When kids are bored by unimaginative (read: safe) playground equipment, they're less active as a result, and with childhood obesity at epidemic proportions, that's a danger, too.