If you are going to transfer big files over sftp/scp on a fast network, I would recommend using blowfish encryption. This speeds up stuff a lot. (Faster upload download)

You can specify the encryption for scp by -c argument. For example:

# scp -c blowfish hebelek.tgz remoteuser@remotecomputer:/tmp

(If you are thinking how to type bold letters on a console… Please don't use sftp… )

OpenSSH rules