How about this for a science fair project with real-life results.
Middle-schooler Ellie Lammer of Berkeley, Calif., had noticed that a parking meter expired before the set time. She wondered how many other meters kept incorrect time. For her science fair project, she took a bag of nickels and a stopwatch and tested 50 parking meters. She found that 94 percent did not keep proper time; 66 percent were slow, actually giving away parking time, and 28 percent cut off before the set time, shortchanging the consumer.
Her efforts led to a new state law, which makes county departments of weights and measures responsible for handling complaints about meters. Berkeley officials also installed new meters, which Ellie duly tested. Her report: Accurate to within six to 10 seconds of the specified time.