I grew up around Duct Tape. I'm from a small town and watched a lot of Red Green so I learned at a young age that almost every household problem can be solved with Duct tape. That's why I've known all my life that placing a strip of tape over someone's mouth will have little to no effect at stopping them from speaking.
And yet movie after movie and tv show after tv show uses this trope incessantly, often basing their plots around it. From Mission: Impossible to 24 to even Once Upon A Time during their season finale. Simply put: It. Does. Not. Work. But why tell you when I can show you. Watch the video.
(read more after the jump)
It's no knock against Duct Tape. The stuff has saved my life at least twice and in Jr. High my wallet and the suit I wore to the halloween dance were made out of it. That last one was a very bad idea, not only is Duct Tape not a flexible or breathable material, it has a very distinct smell that can become overpowering when you're covered head to toe in it. Whoulda Thunk?
So, for leaky pipes, a makeshift sling or a wobbly table leg: use Duct Tape. If, however, you're a villain/psychopath/terrorist and need to keep someone quiet I would suggest the butt end of a gun or, you know, a bullet (I'm old school like that.)