Just switched to Lion on a new Air and I'm trying to get used to all the new gestures. Under Snow Leopard, I would regularly drag a file with my thumb and then gesture up with four fingers to reveal a barren desktop, onto which I could drop the file. I can't seem to figure out how to do that, anymore. By default, the four-fingers-up gesture brings up Mission Control. I can make that a three-fingers-up gesture instead, but then four-fingers-up is unassigned. How do I bring back my old behavior? Thanks.