Chris from PyroElectro sent in this link to his project post for a device which generates some chirping and buzz-like noises every few minutes in order to slowly drive people nearby insane. The circuit consists of a PIC 10F202 MCU, two caps, CR2032 battery and speaker. He built the project as a way to illustrate to beginners how you can make such projects extremely small with the tiny (and inexpensive) surface mount parts available today.
Via the contact form.
Ah tinnitus, I couldn’t hear a thing!