In case you might care to try these, here is a list of the plug-ins I use on firefox:
Adblock Plus (version 2.0.3) Does a great job
DoNotTrackPlus Super great,highly recommended. turns off tracking sites.
FlashBlock 126.96.36.199 lots of ads use flash, so it helps.
HTTPS-everywhere by EFF.org if you go to http://nytimes.com it redirects you to https://nytimes.com. works for a large number of sites.
Alexa Sparky 1.6 this actually tracks web use, but gives info about the site you are on, which I find handy, and I like alexa.