Amazon has these PO Box like lockers in certain places. You order something off amazon and you can have it sent to one of these lockers at no extra charge. When your package arrives you enter a code into the kiosk and your locker opens and you take out your package.
Aamazon just annonced it's going to put these in some Staples stores. Which you can read more about here. Staples Is Getting Amazon Lockers
the only down side is packages must be less then 10 pounds and under 11.8 inches on each side. top, bottom, left, right.
So I'm not sure how badly this limits diaper ordering options. Plus it has to be ordered off amazon certainly. Just figured it's worth pointing out.