Try this solution: http://jqueryui.com/droppable/#photo-manager It seems to me just like u wanna it to work.
In droppable callback u can clear droppable element content.
EDIT
Everything you need is in that example ive linked + one thing:
$( "#container img" ).draggable({
containment: "#container",
revert: "invalid",
helper: "clone"
});
Delete (); after draggable