Under Unix, rcp is also frequently used for file transfer; it is discussed in Chapter 18, with the rest of the Berkeley "r" commands. A more secure rcp replacement, scp, is also discussed in that chapter along with SSH, which scp is based on.
HTTP is actually also a file transfer protocol and can be used to transfer arbitrary files.
rsync, discussed in Chapter 22, is normally used for synchronization but may also be used as a generalized file transfer protocol over wide area networks.
Microsoft's NetMeeting, discussed in Chapter 19, also supports file transfer.