The Fork in the Road
A traveller comes to a fork in the road, and he isn't sure which path he should take. There are two men there: one who always lies and one who always tells the truth. The traveller doesn't know which is which, and he can only ask one question to one person to find his way. What is his question?
Hint: The question must force the liar to lie in a way that makes him tell the truth.
Solution: The traveller must ask, "If I were to ask you if I should take this path, would you say yes?" The truth-teller will tell the truth, while the liar will lie about lying, forcing him to tell the truth.
Games

Do Not Press
Whatever you do, you must not press the red button.

The World's Easiest Game 2
As a follow up to the original World's Easiest Game, we've removed all the enemies from the newer version.

The World's Easiest Game
Because the world's hardest game is way too hard.

Pac-Man Made Easy
Because being chased by ghosts is way too hard.
Puzzles
Toothpick Squares
Move two toothpicks to form exactly four squares instead of five.
Connect the Dots
Draw four straight lines, without lifting your imaginary pencil, that touch all nine dots in the grid.
Doorways
Travel through all the doorways exactly once.
Toothpick Equality
Add a single toothpick to form a mathematically true equality.