can I "see" in realtime large file transfers?

Is there a way I can see what users are downloading huge files at any
given time? My itnernet line is sometimes at 98% utilization and I
can't actually "see" who is using up teh whole bandwidth. With
cachemgr.cgi I can see the file descriptors that are in use, is that the
closest I can come to this feature? thanks,

-- 
Fernando Medina Jr.
<fmedina1@dla.co.cr>
ICQ 102329
San Jose, Costa Rica