Well, given the size of an audio file that runs two or three hours, direct transfur over the net, such as through e-mail or IM, is unlikely to be helpful.
As I see it there are three real choices:
1) Hard copy. Sending a disk to whoever hosts the files. IT's slower and does cost some money, but no significant chance of error or data loss.
2) FTP access. An FTP program can hook into a server from any computer, so long as the user has the name and password of the server section. If a dedicated section of space could be set to upload only than it'd work well. Danger is, of course, granting access to hosted files. Not practical from my point of view.
3) Torrent transfur. My favorite option since all it requires is that the host and the sender have their computers on and connected to the internet. The sender bundles their files, creates a torrent file, the host downloads it and starts the transfur. With big files it can take some time but I've seldom had problems with torrents.
