It takes a braver man than I to put a brand new iPhone directly in the beam of a powerful laser (Do you expect me to talk? No, Mr. iPhone, I expect you to die-cut), but that's exactly what the Make blog did. They etched some old school flying toasters right there on the back, and they ended up coming out pretty well.
There are apparently a couple different engraving houses that can get this done, but according to Engadget, their buddy Phil Torrone (who did this cut) is more than happy to do it for you. So if you're in New York and want to put your iPhone under the lasery knife, give him a call.