This is one of the saguaros I saw today while riding the Boulder Trail to the Marcus Landslide Trail.
2013-05-26-DSC09904-mediumBelow is a 1:1 crop of the flowers from the above photo.  I used my Sony RX100 for these photos.  ISO 125, f/9, 1/250 sec with a (35mm) equivalent focal length of 100mm.  (Camera focal length was 37mm.)