From CDT.org:
CDT today released an update to the browser report it issued in October of 2008. The report includes updated information about privacy tools available in five Web Browsers ?€? Firefox 3.5, Internet Explorer 8, Google Chrome, Safari 4, and Opera 10. The report compares browser offerings in three key areas: privacy mode, cookie controls and object controls. Each of those, when used correctly, can greatly reduce the amount of personal information users transmit online.
Browser Privacy Features Report, Version 2.0 [PDF], August 05, 2009:
http://www.cdt.org/privacy/20090804_browser_rpt_update.pdf