We will occasionally mix one of these in. We are really looking for folks that can actually say 'no'. In some cases, we will keep tossing out absurd requirement on a 'how would you' project. One that some use is asking for a method that does not exist -- we are hoping they know the language well enough to say 'you mean this or this?' or how they can actually say I don't know, but I know where I could look it up.

It's gone both ways for me. I had one interview where the interviewer got very mad at me, and another where the interviewer was very impressed and was pleased to learn something. I got an offer from the latter company, and accepted.

Mind games, great sign that the company will be fun to work for