I hate, hate, HATE gimmicky interview questions. At my job I am asked frequently to be on interview panels for my own department and sometimes other departments. It seems like every manager running the interviews throw out these trick questions at some point or another and I just cringe.

There is no magic recipe for interviews. Ask about the person, ask about their experience, see work examples if appropriate and ask some questions to gauge knowledge level for the position being applied for. Anything more and you are just going to second guess yourself out of a good candidate.