I like to monitor our systems with tail -f on the various log files and going back into them if needed to understand what happened but this tool is just too cool. I now keep it running on my desktop reserved exclusively to the tail -f of the log files side by side with the xterms.
I downloaded it on our system from this site, compiled and installed it without any problems. I scanned the directory with f-prot anti-virus after building the program as a non-root user before actually running it just to play safer. Obviously, such a program must run as root to access the network interfaces ;-(
That is the price to pay to get the goodies so please consider before installing, especially if you do not own the system.
Nevertheless, on a busy system, etherape was hogging 1 CPU for itself. I solved this by turning off name resolution of remote IPs and turning off anti-aliasing in the preferences and EtherApe only use 5% of 1 CPU now.
I also changed the "Size Mode" to "Square Root" and raised the "Node Radius Multiplier" and the "Link Width Multiplier" and changed the timeouts values to fit the traffic we get on our sites. As well, I defined more colors so the same color would not get reused for 2 or more different protocols.
UPDATE: We left EtherApe running for 2 days on one of our system and its memory usage raised to 400 MB ! This definitely looks like a memory leak although the leak could be in the version of the libraries we have installed and which EtherApe uses, not in EtherApe itself. This didn't affect our system because it has a lot of memory available. Nevertheless, keep an eye on this especially if you are low on memory. In these conditions, EtherApe doesn't seem do be appropriate to leave running perpetually. Just shut it down after usage or every day at least. One could use a script that would shut it down then restart it.
etherape -i any &
Below are some screen shot of EtherApe at work :