Apparently Coca-Cola does NOT always taste the same.

Coca-Cola made in the US is sweetened with high-fructose corn syrup, but the Coca-Cola made in Mexico is sweetened with cane sugar.

I doubt that I could tell the difference, but enough people think they can to create a market for imported Coke.

See this article in the San Diego Union-Tribune: Is Mexican Coke the real thing?