One problem teachers have is that the school may not give them network storage. So, they either have to copy files from place to place or haul around a laptop. FolderShare allows you to transfer and/or share files between multiple computers. Looks like a possible solution to a very tired problem.
FolderShare.com - sync files, sync folders, transfer files, share files, web download, access files: "FolderShare: Specializing in remote access and file sync allowing you to keep your files sync'd over the Internet & LAN, share files with others, and web download access to your files."