Ok a little screenshot is perhaps better than a long talk.
Yes, I use gkrellm to monitor my WRT (mainly the bandwith, CPU Load .. and other stuffs). This is pretty easy to use, and friendly no ?
update: I miss the URL: http://chriscarey.us/software/gkrellm/wrt54g/
What version of openWRT do you use?
http://chriscarey.com/software/gkrellm/wrt54g/
he changed .us to .com