Since you've gotten into electronics, haven't you wondered if there is a fart sensor out there? I sure did. I discovered that if you use a methane sensor, especially the MQ-4, even at very low concentrations, it reads farts. What if you combined that into a hat with an LED Bar Graph and a XBee? Exactly. The Gas Cap was made with that in mind. For around $100, you can build your own Gas Cap, a human gas-operated LED Bar Graph on a hat. So, you fart into the methane sensor, wirelessly transmit that data to the hat, and watch the LEDs light up so that your friends can see how horrible it was.
Feel free to leave any questions or comments.