Here are some great sources of intriguing philosophical quizzes that you can do alone, or with a small group of friends. I've enjoyed them both ways.

Morality Play: A fascinating quiz that determines how you weigh truly difficult ethical situations, and compares you in the end to other respondents.

Ethical Philosophy Quiz: Ayn Rand or Thomas Aquinas? Aristotle or Spinoza? Take this quiz to determine which philosopher is your most kindred spirit.

What philosophy do you follow?: Similar to above, but instead of philosophers, it matches philosophical schools of thought (Kantianism, Utilitarianism, Existentialism, etc.)

What's your religious philosophy?: Very short, and gives you a cute little embeddable result for your blog.

Staying Alive: This intriguing quiz will determine what you personally define as life vs death, and whether you're consistent about it.

Belief-O-Matic: What religion suits you best, based on your beliefs and sentiments on a wide range of issues? 27 possible results, ranked based on match, from Islam to Theravada Buddhism, are included.

DIY Deity: What characteristics does the Supreme Being have? What is actually possible? Can God be both omnipotent and omnibenevolent? Both the Creator and the Sustainer? See if your assumptions even make any logical sense.

Political Compass: How do you fit on the authoritarian vs libertarian, and left vs right, axes? And how do your results match up to people like George W Bush, Gandhi and Stalin? Gives you your result in a grid with other prominent political thinkers. This "iconochasms" quiz shows some really surprising sentiments among leaders you thought you knew so well.

Academic quiz: Tests your knowledge (and applicability) of what you learned in Philosophy 101. You might want to consult one of the books to the right, like Sophie's World, if you get a failing grade. ;-)

Interactive quiz: Similar to above, but it fires up your competitive spirit by pitting you against a computer opponent.