And for the chat.
For instance, say you are writing a quick note to someone (via chat) and you want to show them a small image. It would be nice to drag that image from your desktop or folder into the chat window and the person on the other end could see it.
Or, if this could be done in gmail instead of having to attach a file. Make it so that you can drag and drop an image into the composition window, just something at screen resolution so that you can "show" someone a quick pic.