I've seen television shows where interviewers literally seat prospective employees in chairs where the front legs are inches lower than the rear, giving the seater the feeling of falling out of the chair during the interview.
The company will only consider people who stand up and state they would rather continue the interview STANDING than to fall on their face in the rigged chair!
There are lots of ways to test a possible employee...
When I was young I tried out for a car sales man job, the interviewer handed me a Desk Staplegun and said "Here, sell this to me" I went right into Beemaster mode and asked him what he wanted it for, he come up with some fictitious company, I proceeded to explain we had many models from light to heavy duty, great discounts on quantity purchases, colors which match any office decor, etc.. When finished, I boldly asked, "So... how many cases would you like to buy today?!"
I got the job, did very well at car sales and couldn't stand it, it was a terrible job which I would never repeat, although I did quite well for nearly four months. Today, if I had to reenter the job market in sales, I think I'd go for consumer tech sales (Best Buy type) of job - I know it wouldn't be making the kind of money us Fed employees make, but I think I'd like what I do :)
Good luck Mick, keep us posted.