It was interesting to note that this past weekend when we were in Pennsylvania each time we ate at a restaurant and the children invariably left some food that they might eat later, when we asked for the rest 'to go' the wait staff always bought a box or carton to the table for us to do it.
My wife and I could only come to the assumption that the wait staff were not lazy but the restaurant was fearful of some frivilous consumer lawsuit from being given either the wrong food or food that became contaminated somehow.
If anyone has a different explanation I would be interested to hear it!
If you are dealing with clients in the US (or elsewhere for that matter) have you looked in to the legal implications of what you promise?