Drag/drop on monitor-spanning Finder windows

In OS X Leopard (can’t confirm earlier versions), if you have a Finder window spanning multiple physical monitors or multiple virtual Spaces, or extending off the edge of any physical monitor, try dragging a file and dangling it over that Finder window.  The Finder window will smoothly slide into the current physical monitor on the current space, giving you access to all the visible contents of that folder.  Drop the file or unhover and the window will smoothly slide back to its original position.  Nifty.Bonus tip: set up a corner to activate Spaces and another to activate Exposé.  Now you can drag a file to any window on any space without touching the keyboard.