The best trivia games and quizzes on the internet.
With over 800 games and quizzes on this site with varying skill levels, there is something for everyone here. Some are standard quizzes such as "European Countries" or "Asian capital cities." However some get you to reorganize your global knowledge in ways you've never considered. For example, What is the most populous city in the world for each given time zone (not that easy right)?
Via Seth Dixon