Nor had I. Here are a few other references I found in blogs and news groups. Instructions seem pretty consistent, but no mention of the origin or symbolism. Are you paying the devil a pin to get your glasses back? Pinning down the demon who stole your keys?
My auntie used to do this to find lost keys and things. You sit on the sofa with a pin, and you trace a circle on the arm of the sofa in an anti clockwise direction; as you do it you say I pin the devil. You do that 3 times and then stick the pin in the centre of the circle; as you so that ask for your thing back by name. It'll turn up within 3 days, then you remove the pin. Its spooky but it works.
This method has been used in the Cornwall area of the UK for donkeys years (a long time). Because of its origin I tend to think it is linked to witchcraft and sometimes the results are quite spooky. What you have to do is take a pin and recite out loud "I pin the Devil" three times and then stick the pin in the back of your usual chair.
When you are looking for something you have lost, take a pin and stick it in your notice board (or something suitable) at the same time say out loud, "Pin the devil."