Sometimes, when I'm really bored, I'll play "Six Degrees of Wikipedia". Go to Wikipedia and click the "Random Article" button. Then open a new tab or window, and do the same thing again. The idea is to get from one article to the other by doing nothing but clicking imbedded links, and by clicking as few links as possible.

For example, if the first random article happened to be "Mickey Mantle" and the second was "Henry Hudson" you'd probably find a "New York City" link in "Henry Hudson", a "New York Yankees" link in "New York City", and a "Mickey Mantle" link in "New York Yankees". That's an easy example.