Can it be done?

BitTorrents has become so popular. But it makes you wonder: so many people are downloading the same stuff over and over. So essentially there is redundancy. Sometimes it happens that the same torrent piece is getting downloaded by two people that are nearby geographically. Suppose I am some where in Cincinnati, OH and my friend interested in the same file is in Cleveland, OH. The file is being copied from someone in Poland say. So the same piece of the file is being sent across the Atlantic. Can’t we somehow figure that the pieces have a common node somewhere and then send only one copy across, then make two copies of the material at the common node, and send off each copy towards their final destination? Won’t all this be much better than sending two copies of the same file? Maybe they already do this? We can even do something like this for other stuff that’s frequently downloaded – like stuff from download.com. Can’t this same funda (idea) be applied there? How about if we wait a milli-second, figure out all the stuff that’s going to Japan, bunch all of them together in one large packet, and send it across?