One day while walking to lunch about noon near Los Angeles, a friend, David Lumley pointed to something strange in the sky. I believe this is an example of a circumhorizontal arc. At that link you will find an explanation and see a nice gallery of examples that resemble mine. At first we mistook this phenomena for one known as "sundog". I excluded the possibility of a circumzenithal arc when I noticed the sequence of colors. Here's a nice reference for all kinds of Atmospheric Optics.
I put my pictures in the public domain. Feel free to copy. Enjoy!