This plain white box has its house number and a saguaro between the posts:
I found it (and the box at 3307 North Fontana; see tomorrow's entry!) on May 20, 2013.
P.S. The last half of last year was sooooo busy that I had to cut the number of mailbox “posts.” But I'm back on my bicycle, and I'm hoping to get back to posting boxes every day — at least, every weekday.