Monitor Network Traffic with EtherApe
I wanted to count packets coming back and forth while telnet'ing to test out some different email protocols on our mail server and found this nifty little utility: it's called EtherApe. Supposedly it's a clone of Etherman, which, if it has clones, probably costs money.
(http://picasaweb.google.com/lh/photo/jNWdHI8V5W1IIMh1W1NKYw?feat=embedwebsite">sudo apt-get install etherape
There will be a few libraries that are dependencies, but I forget which they are.