What unusual or useful interview techniques do you know of or can think of?

The question comes to mind from this post by Wynn in another thread:
Quote Originally Posted by wynn View Post
It's like the story of the boss when hiring staff set up the interview by first putting a sheet of paper on the floor, the first person to pick it up and hand it to him got the job.
Good one Wynn

Here's one I "suffered" when being interviewed for Eskom many (many) years ago.

The interviewers are set up behind a table at one end of the room. The interviewee, upon entering the room, is directed to a single chair placed at the other end of the room. One of the interviewers then "has a hearing problem," constantly prompting the interviewee to speak up.

Good marks for the interviewee who doesn't get rattled. Full marks for initiative to the interviewee who picks up the chair and moves up to the table.