Oooh, an intellectual's game. I'm in. :D
Hmmm...I guess we'd have one less biodegradable material in the world, and there would be more glass used instead, probably. More glass means higher chances of breaking, and more chances of injury.
My guess would be less diverse cultures, but probably a greater feeling of oneness. Racism would no longer be an issue, at least.
Suppose there were never multiple religions. All was one, instead.