Not in the Greater Phoenix area, but down the road at bit (in Tucson):
1. Center for Creative Photography, University of Arizona (exhibits and archives of Ansel Adams and other major 20th Century photographers): http://www.creativephotography.org/collections
2. Etherton Gallery - many exhibitions and gallery photographs: http://www.ethertongallery.com/
3. The University of Arizona Museum of Art (primarily paintings, but some photographic exhibits): http://www.artmuseum.arizona.edu/eve...-good-likeness

Jim