The other day my AVG FREE install notified me of another free privacy and blocking feature I could activate.
It's called Privacy Fix and is accessed through the AVG Zen panel. It allows you to opt out of sharing personal data, tracking cookies and social buttons and widgets. It also specifically turns off Google search history, what you watch on Youtube and your +1's, comments and reviews that Google could use in delivering ads to you. It also blocks personal data from Facebook, Twitter and Linkedin. One aspect I particularly like is the display that shows how much (in USD) that Google WON'T be making off your personal data when you enable these features. So, if you want to keep your data to yourself, give it a try.