IE: http://nakedsecurity.sophos.com/how-to-disable-java-internet...
Firefox: http://nakedsecurity.sophos.com/how-to-disable-java-firefox/
Chrome: http://nakedsecurity.sophos.com/how-to-disable-java-chrome/
Safari: http://nakedsecurity.sophos.com/how-to-disable-java-safari/
Opera: http://nakedsecurity.sophos.com/how-to-disable-java-opera/