"Now a lot of people didn't know that (self included!), but they do now. Thanks Danny!"
Surprisingly it's actually quite well known and I was reading about it only a week or two ago in the context of Malta. It's even on the Spitfire's Wikipedia page.
(Which also tells us that if fitted with a 170 gallon drop tank, a Spitfire could fly the thousand miles from Gibraltar to Malta and that twelve of them did.)
This made me laugh (Malta again):
“On one occasion all our fighter aircraft were grounded in order to try to increase serviceability. The Hun bombers came over in force with quite a large fighter escort. It happened that there were several fighter pilots with me in the Operations Room, one of whom was a Canadian with an unmistakable voice. I put him at the microphone at a stand-by radio set and proceeded to give him dummy orders. He replied just as if he was flying his fighter. This, we suspected, caused a cry of ‘Achtung! Spitfeuer!’ to go over the German radio. In any case, two 109s enthusiastically shot each other down without any British aircraft being airborne. This knowledge that the Germans intercepted our orders stood us in good stead. We claimed that Pilot Officer ‘Humgufery’ shot down the two Huns.” P/O Woodhall
And sorry for the thread drift but this is another fascinating fact: in two months the Axis powers dropped more bombs on Malta than London received during the blitz.