Hmm... Good question... Bit torrent might be worth looking into. It will probably take forever, but once it gets going you can just leave it for a couple days and it's easy to resume a transfer if anyone gets disconnected.
It might even be easier and faster to go low tech. A few DVD-Rs or Flash drives and stamps would do the trick.
Agreed. I work on recording projects with musicians all over the U.S. For huge data files, a DVD in the mail is way more convenient than the internet, and possibly even faster, if you factor in next-day delivery and less-than-robust network transfers.
It might even be easier and faster to go low tech. A few DVD-Rs or Flash drives and stamps would do the trick.