I work in an IT startup with 2 partners, and I'm the programmer/IT guy -- in other words, the work horse. To make a long story short, I'm doing most of the work right now, while they spend all day on Facebook. That's OK, because they're paying my salary, but if the project fails, I'm sure they'll blame me for it (I'm doing my best to make sure that doesn't happen!), and I want some sort of recourse. I already have an app that blocks time-wasters on my local PC, and keeps logs of when the app is enabled (so I can say "I had Facebook blocked from 9am-5pm today.")

Is there any way I can get a brief summary of the most heavily visited sites, split up by client PC? At the end of the month, I want to be able to say "You both load Facebook, on average, every 10 minutes. You spend hours a day on Youtube, and haven't opened up our bugtracker in weeks" and maybe have a nifty chart or graph to match it.

We have a crappy D-Link router, and no IT budget. They are both on Windows Vista, I run Ubuntu Linux. I don't want to install any monitoring software on their PC, but I'm totally fine with, say, routing all the network traffic through my machine.

I guess I can think of lots of ways to accomplish this (telnet into JSSH and list open tabs? log all the DNS requests, per-domain? even thinking of setting up a webcam on my desk and just keeping 5-minute snapshots...), I just don't really know where to start. Any advice is appreciated, thanks!