An eye opening look at Internet tracking, Lightbeam for Firefox: Privacy Education for Users & Open Data for Publishers.
Lightbeam is shockingly good at visualization of tracking data (it does not block anything).
The Chrome version is called Collusion (Lightbeam's original name).

Looks interesting.

I saw a reference to this utility the other day. it looks useful and I'm definitely gonna try it.

Have you used the tool: EtherApe?

It's another visualization tool that allows you to track your local and internet traffic. Very useful for determining which apps are connecting to the internet and who they are communicating with.



iftop is another good command line tool for monitoring network traffic.

I just downloaded EtherApe, it looks interesting. I've used WireShark before. Lightbeam is fairly basic in comparison a handy addon in the browser.