I was browsing a list of "the worst inventions ever" and stumbled across this beauty, amongst such other wonders as the inflatable dart board and pen that works in 0 gravity (more on that one later!)
The one that made me laugh the most was the prank deterring fire alarm. It was designed to keep pranksters from falsely pulling fire alarms. The contraption worked by sticking your hand through a metal tube, and then pulling the alarm mechanism. Upon pulling the mechanism a hand-cuff type device would lock onto ones wrist until a fireman or police officer with the key came and let you out, along with a scolding for what you had done.
So what was to happen in the instance of a real fire? I guess people were supposed to play paper, scissors, rock to find out who was gonna take a hit for team before pulling the fire alarm. Certainly near the top of stupid ideas! Here's a picture I found online.
<img src="http://www.craphound.com/images/firealarmholder.jpg">
"Looks like I pulled the short straw!"
As for the zero gravity pen, NASA spent tons of money trying to develop a pen that would write in the zero-gravity environment of space. It turns out they were successful by pressurizing the ink cartridge, of which is now widely available. When faced with the same issue, the Russians were able to find a much cheaper solution to the problem, they simply used Pencils!