I just saw this. It's a clip from "The Comedy Barn." Wade through the first couple minutes; it'll be worth it. (And stick around 'till the end; it's kinda fun what the schtick was that they were ending with.) The guy with the world's stupidest laugh is the one in the middle. According to the note from the man who submitted this, the man is the submitter's father and that is definitely his real laugh. How he reproduced is a wonder.