Here's how to do it: Move along at a moderate speed (it's quite hard to pull it off going slow) and place you feet in the ollie position, but with your feet facing the nose a little more than usual. You need to keep your feet in this forward angle to get a good pop and pull off the trick successfully. Now, pop with your back foot real hard and slide your front foot off the board and out of the way. Spread you legs, letting the board do half a backflip between them. Turn your body 180 degrees (frontside) and catch your board and land on the trucks, riding away fakie.
This trick is hard to explain in writing, so watch people perform it and keep on trying.