Use a Trustworthy Search Engine
Avoid Allowing the Other Search Engines To Track You
In FireFox 1.5.x
Edit -> Preferences -> Privacy Tab -> Cookies -> Exceptions
Then add the Google domains you wish to block/allow. This will result in many random cookies being generated by Google for each search done (as they will think you are a new comer each time). Personally I white-list all my cookies, only allowing the sites I trust to set cookies, which are then automatically cleared when I close FireFox.
Also do not use GMail via the web interface, it is possible to use GMail via an email client residing on your computer.
From there you can use your choice of email Encryption/Steganography as you see fit.
You can only be controlled, if you allow it.
You can only be surveyed, if you are unaware of or ignore it.
It’s your choice.