Ah! A nodeshell to rescue!
Ever want to be the life of the party, win friends and influence people? Show off your (drumroll please) amazing ability to short circuit the language center of the human brain?!?
Do a couple of these tricks with a small (no more than 5) group of people and you'll be guaranteed all these things ... and more (like the girl who slapped me because everyone laughed at her for falling for these pranks).
Try them on your best friend, then check the bottom of this writeup for the results I've most commonly observed. Then go Broadway baby!
One
Ask someone to "say the word tin, like a tin can, out loud, ten times."
Then ask them what an aluminum can is made from.
Two
Ask someone to spell the following words:
folk, as in folk song
joke
coke, as in Coca-Cola (or cocaine, depending on the party)
Then ask them what the white of an egg is called.
Three
Ask someone to spell the word fort.
Then ask them what they eat their cereal with.
Four
Ask someone what they would call a spooky thing that haunts houses.
Then ask them what one puts in a toaster.
One: Nine times out of ten, the person questioned will say an aluminum can is made of tin, so ask them several times to make sure.
Two: Again, about 90% of people will say "yolk" as in egg yolk, instead of white. And as Azure Monk pointed out, a statistically insignificant number of people will actually answer with albumen. Mostly doctors, for some reason.
Three: Most times, you'll get the word fork for an answer. It's most amusing when they actually spell fork.
Four: Yup, you're catching on ... most people say toast. However, if you put toast in a toaster, you get burnt toast. The correct answer would be bread, but people will quibble with you if they've hung around this long and haven't murdered you out of their own embarrassment. | 
