Around 40 percent of Fortune 500 companies require job candidates to take personality tests -- that's nearly double the 1999 rate, according to a Wall Street Journal report.

You can find thousands of these tests online. Some of them are serious psychological profiles, others are just plain fun.

The Keirsey Temperament Sorter II
Hailed as the "Internet's Number One Personality Test," the KTSII ranks test takers as Artisans, Guardians, Rationals or Idealists.

http://www.advisorteam.com/user/ktsintro.asp

The Jung-Myers-Briggs
A mother-daughter team developed this popular test using the teachings of psychoanalyst Carl Jung. It pinpoints personality using four scales: Extraversion/Intraversion, Sensing/Intuition, Thinking/Feeling and Judging/Perceiving.

http://www.humanmetrics.com/cgi-win/JTypes1.htm

International Personality Item Pool
Choose the 300-item version for the most accurate result.

http://cac.psu.edu/~j5j/test/ipipneo1.htm

The One-Question Personality Profile
I didn't think one question could possibly determine my personality, but this test did almost as well as the more complicated Jung-Meyers-Briggs.

http://soli.inav.net/~catalyst/Type/mbtione1.htm

Find Your 'Star Wars' Twin
Think this test is all fun and games? Think again. The site reminds visitors that the test is "well-accepted and widely used in the personality field of psychology." Sure, and Darth Vader is Luke's father.

http://www.outofservice.com/starwars/

This article originally appeared in Job Tip of the Day. Some of the links may have expired since its original appearance.