Back in the day, people used to blow on a game cartridge to "unfreeze" it. Proving that the NES really is the best gaming system for mods, Batsly Adams put one and one together and made an NES breathalyzer — complete with a game that checks for inebriated pals.
Adam's NES cartridge mod goes by the name "DrunkenNES." Users blow into the modded cartridge that contains a breathalyzer. The breathalyzer then sends the alcohol level data to the custom-programmed NES "game," displaying a person's drunken level.
Get drunk enough and you can enter the game's "Alco-Hall of Fame" — how clever! If we had to rate it, DrunkenNES ranks near the top for most bizarre uses for an NES. That NES guitar from a while back is quite tame compared to this mod.