For those of you in California, Reeves Journal is reporting that California will adopt the 2006 Uniform Plumbing Code (Reeves Journal, October 2006, page 20). According to them it will take effect after January 2008. Until then California is operating off of the 2000 UPC with California amendments.
Last I heard California was considering the International Plumbing Code. Apparently, talks between the two groups as to forming a single code have been called off.