imakeprojects.com started recently with the promise of delivering one project every two weeks. Yesterday was their second release: sonic grenades! They picked up a couple 110dB personal alarms at the Dollar Store and modified them. Now instead of going off immediately, there is a 5 second “fuse” indicated by a flashing LED; giving you plenty of time to lob it into your roommates space. After a minute of being active, the grenade will start chirping every 10 seconds until you replace the pin which should help you find it. There’s a video demo at the bottom of the page.