Ed - What an awesome shot! I'm jealous. I was thinking when I was out there how neat it would be to see it in the rain as it seems so rare out there. Did you see any rocks moving while you were out there? It was amazing to see how permamnent any footprints or tracks become once the surface dries up.
Unfortunately, the friend I was with had a job interview the next day so we didn't have much time to hang out so, no I didn't see any rocks moving. The scenery was spectacular though. We also saw water flowing in Death Valley, but it was dark by then, so no photos.