I'm surprised no one has really had any fun with this question. If you could change one thing, why not model it after something Homer Simpson might say? Faucets that have both hot and cold water, but also have beer. Donut trees growing wild (donuts with sprinkles). Topless women who enjoy being hit on.

OK enough "fun". If I could change one thing about the world I think I'd slow the pace of things down. People are always in far too much of a hurry. They rush through everything in life, and things never happen fast enough for them.

Fortunately, this IS something that each of us can change in our own lives, if we choose to do so. That's good, because anything more and we're simply imposing our own will upon everyone else on the planet. If I'm not mistaken, most people seem to have issues with world leaders who do what they think is the right thing. So, why should we be any different?