Convair, a unit of General Dynamics, first used WD-40 to protect the outer skin of the Atlas missile from rust and corrosion. The product worked so well that employees sneaked WD-40 cans out of the plant to use at home.
and
People?s enthusiasm for sending in ideas for using WD-40 mushroomed under Mr. Barry. The uses included preventing squirrels from climbing into a birdhouse; lubricating tuba valves; cleaning ostrich eggs for craft purposes; and freeing a tongue stuck to cold metal.
A bus driver in Asia used WD-40 to remove a python that had coiled itself around the undercarriage of his bus.
I still use it myself for certain things (not everything: there are better lubricants for some situations, but it's a pretty good GP lube).