I visited the Coke museum in Las Vegas near the MGM Grand Hotel a few years back. They showed all the different kinds of drinks they had plus all the different flavors of "Coke" in various parts of the world, many of which I'd never heard of (the Coke products, that is), so they do have different formulas for different locales.
They'd have these little fountains with cups you can drink samples, so I got to taste a bunch of various Coke products around the world. I think the museum was gone the last time I was in Vegas. Too bad.
The name changes too in various parts of the world. For instance in Sweden, it's Coke Light. I guess "diet" may have different or negative connotations in the world.
