A device on sale at iwoot.com is hoping to beat the wet flannel when it comes to waking someone from the land of the slumber.

Called the Sonic Alarm, the “Alarm” grenade is, according to the site “the perfect solution to your problem.”

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 10 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.