Thanks to both of you for your comments..

Betty, on that first one, it cought my interest because the nails were decaying into the background. I thought it was intersting because it shared the same colors and textures with the rest of the ash and gravel around it, but they still retained their shape. Like I was trying to catch them in their decay, because soon they will just corode away in dissapear into the debris on the ground.

Mike, I see what you mean about that second shot. I think I needed to move the focal distance back a little bit further so less of the foreground was in focus, and more behind the nail was in focus. I've waited and looked at that picture many more times to understand what you meant before I replied. It's hard to see exactly what a picture is going to come out like on that tiny LCD of a digital camera, expecially in bright daylight. Next time I'll maybe try manual focusing and shooting at a couple different focus distances.