You might be interested in the report by the Federal Trade Commission last year, it contains a call for "Do Not Track" technology.
http://www.ftc.gov/os/2010/12/101201privacyreport.pdf Congress has picked up the idea and there are several bills pending to make it into law. However, the bills have not yet been full reviewed by HR Committees nor forwarded and discussed as legislation by the full House of Representatives membership. This is yet another sign of partisan politics that blocks legislation to protect citizen and consumer interests while allowing companies illegitimate profits from tracking consumers on the Internet.
A final version of the report from the FTC should be issued within the next few months, but may be upstaged by the 2012 Presidential election.