One of my favorite metals is copper. It can take on so many appearances, from a shiny polish, to a dull aged look, to the green weathered appearance. This is kind of a neat photo that I did for a challenge called "Pipes" on dpreview. I ended up liking it so much that I made it the wallpaper on my cell phone.
It took quite a few tries to get the lighting the way I wanted. I think it ended up with a nice depth to it though. It almost seems like you could walk in to the picture, and look up at all these huge pipes overhead.