Usecase: Hand over a file to a friend

• Drag and drop a file onto the avatar representing your friend on the desktop
  
• Avatar asks "Is this file intended for me?"
• Confirm question
• File will be added to outbox which should be accessible by your friend
• Your friend will receive a note that you want to hand over a file to him/her, resp. your avatar on your friend's desktop will wave and say that you have handed over a file
• Your friend will grab the file from your outbox