Make:

Instructables user action_owl created this fun keyless entry system using a classic NES, an Arduino, Processing, and a spare CD-ROM.

Once activated NoKES (NintendO Keyless Entry System) will be blinking letting you know that it is alert and keeping guard. Once the Start button is pressed on the controller, the arduino starts recording what buttons are pressed, converts them into a number and adds them together. When you press Start + Select the Arduino compares that number to the combination that you have set.

If you enter an Incorrect combination the arduino activates an attached circuit and plays a sound. It then sends a serial signal to processing and snaps a picture with an attached Webcam (so if someone is messing with your lock you have a picture of them).

If you enter a correct combination the arduino sends a signal to the cd-rom to eject and thus will lock or unlock the door. Upon a correct combination a signal is also sent to processing which plays a sound.

Obviously, this one is a prototype. For anything besides securing your bedroom from nosey siblings, you'd probably want a beefier lock, and the software should check the specific combination instead of summing the keys. With a few tweaks, though, this would be a fun addition to the garage, dorm room, or a boring office space.

Raise your hand if you're thinking of the Contra code right now.

Nintendo Keyless Entry System (NoKES) [via zombie_funk]