There have been quite a few attempts to formulate and disseminate a universal language, none of them particular successful. In general, English seems to be a second language to a very large number of people in various nations and serves reasonably well in this role at the moment but this may change in the future. Language is basic to culture and as the various international communications media with heir various subtypes of entertainment tend to move towards one language that may influence its universality. At the moment mathematics is the only true universal language.

since it's not clear if we determine our language or if our language defines us, it seems to me that this will be impossible as long as we have variation in cultures and peoples. Even in populations that supposedly speak 'one' language, subcultures alter and redefine the language to fit their own ends and to become different. So I don't think that can really ever happen.

Even so, I agree it would be nice. I at the least would like for my own country to speak one language. some interesting banter on the same topic in this string:

http://www.whynot.net/ideas/4059

Incidentally, Esperonto was an attempt at this in the 50s and I recently heard a UN person talking about a simplified English-Spanish mix on NPR that would be a candidate, but I've forgotten what it was called.

http://en.wikipedia.org/wiki/Esperanto

I think the World needs a spoken universal language as well, such as Esperanto.

Your readers may be interested in http://video.google.com/videoplay?docid=-8837438938991452670

A glimpse of Esperanto can be seen at http://www.lernu.net