Did you know you can use the application switcher after starting a drag operation? Start your drag, press Command-Tab, and there’s the switcher. Why might you want to do this? Say you want to drag and drop something into a TextEdit document, but you’ve hidden TextEdit, so you can’t see its windows. No problem; drag the object you wish to drop, activate the switcher, and then Tab over to TextEdit (still keeping the mouse key depressed, so as to not cancel your drag operation). Release Command-Tab when TextEdit is highlighted, and it will activate and unhide. Now you can complete your drag operation, dropping your dragged item into the TextEdit window.