If you have loads of money to spare, feeling itchy and love Google Earth. You can setup Google Earth on multiple screens, this can be on a full wall or all your walls, depending on how many large screens you can have. Ok, you can still set it up with 2 monitors to try it out.
Here is the link on how to set it up:
http://code.google.com/p/liquid-galaxy/wiki/QuickStart
Now would it be more fun if the screens were 3D and had touch support too?