I heard about a good example of out-of-the-box thinking the other day. A college class was given a simple problem solving exercise. They were asked to brainstorm ways to use a barometer to determine the height of a tall building.
The more scientific minds came up with solutions like using the change in the barometer readings from the ground to the top of the building to determine the height. There would be less pressure up higher, after all, and if the barometer was sensitive enough, this information could be used to get within a few feet of the true height.
Another student suggested dropping the barometer from the roof. By timing how long it took to fall, the distance of the fall - and therefore the height of the building - could be determined using the usual formula for acceleration. Slightly more out of the box in his thinking, one student suggested trading the barometer for a sextant. Then he could measure his distance from the building on the ground, take a sighting of the top of the building, and use the angle measured to calculate the height.
That started everyone thinking more creatively. Soon there were ideas like selling the barometer and using the money to buy string, which would be hung from the top to the bottom, and then measured. Perhaps the simplest idea, was to go ask for the owner and tell him "I'll give you this nice barometer if you tell me how high your building is."