The highly anticipated, yet never fail to "trip you up" job interview questions; There's a real purpose behind them. And once you know the reasons for them, chances are you'll be ready for them during your next job interview. Ran across this great article at HuffPo on the subject. Give it a read.
Essentially, employers are looking for three things: First, how quick you are on your feet, your style when it comes to approaching problems and providing solutions, and finally, an indication of how well you're going to work with the rest of the team.
Since there seems to be a somewhat standard set of these seemingly "trip-you-up" line of questions, it should be somewhat easy to come up with an advance set of responses or at least get you in the mindset for answering these types of questions on the fly.
Have you had any unusual questions put to you in a job interview? Share in the comments.