An insight into GUI design: when discussing whether a particular screen needed drag ‘n’ drop, Stephen pointed out that drag ‘n’ drop only makes sense when there is more than one place you can drop the thing. In this case there were 2 lists that were being manually merged into 1. So 2 places to drag and 1 to drop. The more types of things to drag and the more places to drop the better; because the physical analogy is much better.
Of course, there is the other sort of drag ‘n’ drop; the type that is used for ordering items in a single list. For instance browser tabs. That lacks the physical analogy of dropping as you can’t drop it anywhere. I can’t think of a great name but drag ‘n’ snap comes close.