TOPIC: Move from Waiting List to Open spot

When a user registers for an event that is already full they are placed in the waiting list. But when and if a spot opens up in the event, it would be great to be able to move the registrant from the waiting list to the event.
This could be done automatically by checking the registration date. Users registered first would be the one to take the open spot. Or it would still be nice to allow the administrator to manually move a user to the spot.