From Way Beyond The IQ
Dr. J. P. Guilford's book "Way Beyond the IQ" contains the following problem on page 12:
A thermos bottle is standing in the sink, empty except for some ice cubes in the bottom. Your problem is to get the ice cubes out of the bottle. To make the problem more difficult, we shall specify that you may not turn the bottle over, and you have no tongs or other implements with which to fish the cubes out. Your hand is too large to enter the bottle. How can you get the ice cubes out of the bottle?
Guilford's suggests that you ask some friends to solve the above problem and pay attention to the differences in the ways they do or do not solve it. The important point isn't whether or not they solve it, but to get an understanding of how we differ in our intellectual abilities.
1:18 PM
Fill it up with water and it will float the ice cubes out of it.
11:43 PM
Wait until it melts and either let it dehydrate on its own or drink them with a straw...
12:55 AM
Flick them out with a quick upward jolt on the thermos...
1:51 PM
Let them melt, take the water out with a pipe, freeze them back again. :)
11:38 PM
catapult them out by lifting the thermos and then propelling it downward faster than gravity