pfsense why it rocks!
This is a screen cast of pfsense this is just one of its many features but it is one that I like a lot!
As you can see it is giving live feedback of users as they use up bandwidth! If you know who has what IP you can track them down ! And stop them being bandwidth hogs!
It is an amazing bit of software and it can run on an old pc or something from say these people www.yawarra.com.au and that will help to save the trees!
It can also run in a virtual environment so you can create your own little test version of your real world network ...
If you need a firewall / router pfsense is a fantastic open source bit of kit check it out today! pfsense.org