If you want to control internet access, I use surfcontrol (www.surfcontrol.com) You just put it on a box and hang it off the network. There is a free trial so you can test it. That gives bandwidth graphs , site breakdown graphs, type of sites, like gaming, gambling, adult etc. and even a cost, if someone is making 30 and hour and spending 4 hours on a gaming site then that can be broken into a loss chart. It's very nice and after a few visits from admins, people stop it. You can also choose to block sites by catagory or IP or url or type etc. In addition you can have access lists that bypass the sites. Like for CEO and us network people. There is an option I purchase to subscribe to category lists. Where the company catgorizes billions of sites into around 16 catagories. I block ALL access to hacking sites, adult sites, racists sites, etc. Don't wantthose pesky wanna be user admin types getting there hands on an Excel password cracker do we? Block them.

BE Warned, you will have some problems with people after you install this software. Meaning you will find some things you may not like, so MAKE SURE users are aware of your intentions and that you communicate what is going on. Then make sure you have some written policy on how to handle people who just won't stop going to everypornsite.com every chance they get . I chose a less active approach and just started blocking the sites. After I started running a warning banner at each log in for a month, before actually starting the log process. I wasn't out to "get" people and I still aren't. Just want to free up some bandwidth.