Stan Lee is the godfather of much of the Marvel Universe, including The Fantastic Four, Spiderman, X-Men, Iron Man, and many more. Today he spends much of his time dropping into cameos for the Marvel superhero films; most recently, he was seen as the old man in the school library in The Amazing Spiderman).
However, he once crossed over into the DC Comics realm to reimagine the major characters in a series called Just Imagine Stan Lee. In his reimagining of Superman, Superman was a Kryptonian named Salden who was the weakest member of the Kryptonian Police Force.
He used a flying harness and was transported to Earth when trying to capture a criminal in a teleportation lab. Salden decided to become a superhero on Earth to rid the world of its problems.
Batman was renamed to Wayne Williams (Stan Lee had a thing for alliteration in names http://www.omg-facts.com/view/Facts/34752). He was changed to a rich African American whose father was a murdered policeman. Wayne vows revenge on a gang leader named Handz who framed him for a crime, and soon becomes a wrestler named Batman.
Batman gains notoriety and eventually defeats Handz before deciding to fight for justice. He reimagininged most major DC characters and even the Justice League. They are all pretty clever, and you can read about them at the source