lftp (
http://lftp.yar.ru) is absolutely brilliant. It supports FXP (site-to-site transfers) and dropping to background. It's really useful. I often SSH to my account at work and start a download using lftp, then exit and log off. lftp will continue in the background and exit when the download is complete.
If you want a client with a quasi-graphical interface for use in a terminal you could have a look at pftp (
http://www.tanesha.net has a distribution of pftp with excellent TLS/SSL encryption support).
hw