WarKirby
What is the best way to transfer really large files over the Internet?

By that, I mean several gigabytes.

It really depends on what the data is. If it's like a DVD's worth of data, I'd say bittorrent would be the best way to get it out there for people to download. If it's not copywritten, you could look for cheap web hosting that will let you add multi-gigabyte files to the account purely for downloading purposes. If it *is* copywritten material, distribution can make things tricky to spread it around the Internet.