Web browsers: All major browsers include options to transmit Do Not Track headers to websites to signal that a user does not wish to be tracked. among their settings. (Internet Explorer and Firefox)
Blocking tools: Block communication with websites matching entries on a Tracking Protection List. (Ghostery, TACO, AdBlock Plus, and IE9 Tracking Protection)
Ghostery and Ad Block Plus is the ones I hear about the most.
Haven't tried any of them.
Behavioral marketing: Why Johnny can't opt-out
When surfing online remember Sturgeon's Law: "90% of everything is cr@p."
© Gregori Potemkin. All rights reserved. But wait . . . fair use allowed and encouraged. Actually, go 'head and publish the whole thing as is. I don't care.