I have once heard a legend. It was about the birth of different languages. It was something like that… People were building a town and while working they started to argue about the building process. This argument grew into a quarrel, which took too long to listen to patiently. So God got bothered with this quarrel and arguing and made people speak different languages, thus they couldn't understand each other. They stopped arguing in vain and carried on building. I don't really remember if the town was built or not….I suppose not because it's difficult to work without understanding, but that was God's decision, without comments.
My idea is what if all people in the world spoke one common language. I guess it would be much easier to communicate and there wouldn't be so many barriers between nationalities and maybe it could decrease some national conflicts.