
Actualy, you CAN change the graphics on the iPod Mini.
However, you have to reinitialize the iPod as the software for doing this is only available on Windows. It basically mods the firmware in your iPod to replace the graphics; however, if you do this, your iPod will be associated with your PC AND you won't be able to use your iPod as a portable hard disk on your Mac

Otherwise, I would do it in a heartbeat.