This sonic grenade is marketed as a tool for waking up recalcitrant loved ones:
The Sonic Alarm makes the whole 'getting them out of bed' exercise a very simple, and indeed amusing, operation. Looking like an old-fashioned comedy hand grenade, the Sonic Alarm will wake pretty well anything up. Simply pull the pin, yell an emphatic "fire in the hole" and lob the grenade into the sleeper's room. After ten seconds a very annoying and piercingly loud noise (there are three volume settings) will blast out from the alarm. That's not all however, what makes this especially great is that to stop the alarm the sleeper has to find you so you can put the pin back in. It's stupid, and brilliant, and will be the bane of every over-sleeper on the planet.
(via Red Ferret)
