I live in Edinburgh, where public transport consists of a wonderful bus service (and an upcoming tram line which has been a complete fiasco from start to finish).
Catching buses I've frequently noticed that other bus-drivers would hop on and off the bus, traveling for free, presumably on the way to stops to change drivers etc.
I figured if I dressed up as a bus-driver, in their simple uniform, I could hop-on and off buses for free. I didn't intend to defraud the company, but was curious to know if it was possible.
Short version: Free bus travel for a couple of days, providing I wore the maroon blazer, smart trousers, and carried a bag.