said by bondo :
I've been trying out this freeware called PRTG traffic grapher, it monitors my whole network by looking at the SNMP on the router. so far seems pretty good, because I have about 7 computers hooked up to the router.
I second PRTG. I run it on my windows 2003 servers, works great. You get 3 free different monitors of whatever you want to qualify as freeware, after that you must purchase the product. It's a little more advanced and designed to run in a server setting.
edit: nvm I guess they changed it now they offer 10 free monitors with their new product as freeware.