Do a Google image search for batman steampunk
. There's lots of interesting stuff out there. Here's a picture
of a steampunk Justice League.
As for Elseworlds and different versions of Batman, my favorite is Speeding Bullets
. In that story, Kal-El's ship lands just outside of Gotham City and he's found and raised by the Waynes. They name him Bruce and he grows up to be a super-powered Batman.