Drag and Drop
Imagine a library where you’re free to browse the stacks, but when you pull a book from the shelf it’s magically transformed into a card which says, “You’re holding one book”… until you set it down on a desk or the checkout counter, at which point it magically changes back into the book. The real world doesn’t work like that—neither should the computer.
Perhaps it is encouraging to note that in X.3 the dragging and dropping of single e-mail messages in Mail has been improved.