I've heard talk about it, but I don't exactly know how I download and get it running. It seems fairly helpful. Any help/links is appreciated.
Be sure you configure your options to show PR. It has some warning about sharing info, and sometimes will default to disabled. Let me know if you have further questions.
There are quite a few https://addons.mozilla.org/en-US/firefox/search?q=page+rank&status=4 I used about 4 of them. They all do the job.
I like the one for FireFox here: http://www.quirk.biz/searchstatus/ it has Alexa, Google, and Compete all rolled into one, and it tucks in nicely up in the menu bar (to the right of the FILE EDIT VIEW list) of course I still have the googlebar installed, as I find the find & spell checking features indispensable...not to mention the search
I don't see a reason why someone should install this spyware. There are so many other ways to check your PR.