Ghost Drag

http://www.jroller.com/gfx/entry/drag_with_style_in_swing

http://www.java2s.com/Tutorial/Java/0240__Swing/DragandDropSupportforImages.htm

http://docs.oracle.com/javase/tutorial/uiswing/dnd/dropmodes.html

http://docs.oracle.com/javase/tutorial/uiswing/dnd/droplocation.html