On my version of FF the icon is up next to the URL box.
Wouldn’t it be cool if the installation gave you several possible places to place the icon?
Take a look at TrackerBlock from http://www.privacychoice.org/
Hmm... I have the latest version of FF, but I only have the Ghostery icon and my video downloader visible in the address toolbar. Ah well, finding Collusion is way down on my list of priorities right now.
Cool tool, though. Thanks for turning me on to it.