I totally agree, every surfer should either be a member of Surfrider or Surfers Against Sewage.
If you don't know anything about them then check out their sites - SAS is UK based and Surfrider is US based.
Join up and help support what these guys do - it's not much money for membership and they have special rates for students / families etc.
Stop reading this forum and go sign up now
http://www.sas.org.uk/
http://www.surfrider.org/