The Campaign for Peace and Democracy
    A petition endorsed by heavy-weights like Noam Chomsky,
    Daniel Ellsberg, Arundhati Roy and many more
    http://www.cpdweb.org/

  Refuse Canadian Military Involvement against Iraq
   http://www.petitiononline.com/810947/petition.html

  A Global Appeal for 'No more violence!'
    http://www.flora.org/coat/appeal/

   Iraq Peace Pledge
    http://www.peacepledge.org/

  No War with Iraq
    http://www.e-thepeople.org/a-national/petition/2842/view

   Let the Inspections Work
    http://www.moveon.org/

   National Network to End the War
    http://www.endthewar.org/frontps/UNWHOpetition.htm

   Vote To Impeach Bush (for American residents only)
    http://www.votetoimpeach.org/

   Vote No War (seems geared for American residents )
    http://www.votenowar.org/

   Petition to get France to Veto UN Security Council
    http://www.veto.ht.st/