Internet quizzes can be fun, but this is a seriously useful site, where you fill out a questionnaire about your characteristics and lifestyle and it tells you your "real age"--a backwards way of saying, your life expectancy.
What is most useful is that it is totally specific about what answers caused the number to go up or down, so you can adjust your lifestyle to see what effect that has on your "real age." I get the email newsletters--they are tailored to my specific profile, and they have been quite useful. I know enquiring minds want to know, so I'll report: my chronological age is 48.2; my "real age" is 43.2. I have healthy habits and good genes, but I could improve by eating more vegetables and whole grains. If I also started eating soy products regularly, I might live forever. Tofu burgers! I don't think I'm quite ready for that.