How do you change the serial number in a IPod Touch?

The serial number on a Mac is burned into ROM on the main logic board. What that means is that only Apple Authorized Service Providers (AASPs) have the ability to set the serial number on a logic board using a proprietary Apple software tool. The serial number can only be set once; it can not be changed afterwards. If your Mac has been repaired recently and the serial number as reported via 'About This Mac' or System Profiler is not set, you can contact Apple via 1-800-275-2273 (in the U.S.) to arrange to have it reset.