Here's a great photo of San Francisco's Golden Gate Bridge at night. I like this picture because it's not your standard Golden Gate photo of the bridge in bright daylight. Sometimes you also see the Gate surrounded in fog. The bay is often foggy, and I found SF to be chilly even in the summer.
Here is another great piece of American architecture (suitable for wallpaper). I remember driving through Memphis many years ago on my way to New Orleans for Mardi Gras, and the Pyramid is very striking. It's huge!
Sad that the arena is not currently being used. I hope they sort this situation out soon, it is such a waste of a great building.