My current tool of choice for on-demand console traffic monitoring is tcptrack.[0] Uses libpcap so accepts the same filtering syntax as tcpdump.
It can be pretty CPU intensive, so I would recommend against running it on production perimeter systems. Also, the 2 second default retention period is a bit short.
I haven't tried hogswatch; judging by the screenshots, it doesn't bring anything more, information-wise, than what's already present in nethogs' terminal UI.
But 0.8.1 fixes the problem described on the askubuntu page the grand-grandparent linked to.
http://linux.die.net/man/8/netstat
similarly for disk
http://linux.die.net/man/1/iotop