Never heard the family crossing the bridge one. Which one is that?

You have a bridge that can only take a certain amount of weight at once without collapsing. It's dark at night and you have only one flashlight. A flashlight is required to cross the bridge, which is traversable in both directions.

You have a family of people of varying weights (the exact numbers you'd have to look up) - determine the optimal way for the family to make it across the bridge.

Thanks. I don't think that's a bad one. In fact, like the Towers of Hanoi, I think it has enough parallels with computer science and engineering to be a good interview question.

Indeed, it is a specific instance of http://en.wikipedia.org/wiki/Knapsack_problem

I've heard the same thing, always from unreliable "I heard" sources. I've never heard anyone who actually did interviews or was interviewed say that.

I was interviewed by Google and had to answer this "brain teaser" kind of questions. So, no, it is not just folklore.

Can you be specific with some examples? As demonstrated elsewhere in the thread, some people perceive the same questions as appropriate and others perceive them as "brain teasers".