There's lots of hidden Easter Eggs in movies, tv shows, software, music, books, and art. And yes there are even some Hardware and Electronics Easter Eggs too!
For example: Like dialing # numbers of your cellphone to bring up a credit screen, game or service menu, etc. Release codes for old american coke machines. Printers have the creators names listed, etc. Apple iPod has a built-in game in game. Clicksor Keyboards have messages from the creators on the display. DVD Players sometimes have Secret Loopholes menus where you can edit the Region ID as well as other things. Some Macs, consoles, Wacom Tablet, etc, all have easter eggs and the list goes on! I know the Nintendo has them in the Gamecude, Wii, Gameboy, etc. There was even Tetris built-in as an Egg on an Oscilloscope!
