French photographer Benoit Lapray has done an extensive series of manipulated photographs of superheroes in natural settings. And a few in urban ones.
I always thought it would be cool (and easy for independent artists) to do a whole comic book/webcomic series using photomanipulated superheroes. I think I've even seen one or two attempts at it, but they all fizzled. So in the meantime, I'll have to content myself with these.