Erm... well, I don't know if somebody else has done something like this already. And I'm not sure if it's technically bump mapping... I don't know much about that either.
Basically, I've got a 3D sphere with an Earth texture put on it, and then another 3D sphere which moves the exact same way with height mapping applied to it. I thought it looked cool.
Can't post a screenshot at the moment, I'm on my MacBook and Apple thought it was funny not to have a print screen button on the keyboard.