All:

If you like puzzles, the URL below leads to one from Google: it's their official Aptitude test, used to recruit potential employees with a particular, problem-solving mindset:

http://www.google.com/googleblog/200...wn-people.html

Taking the test may be useful even if you don't want to work for G. I.e. it *may* allow one "see" what makes the minds of these folks tick -- and better predict (??) their SE's behavior.