Hey Amy,
We're actually in the middle of beta testing an app that will do exactly this. It's already deployed on a trial store, and it seems to be working smoothly. We're working closely with the owners of the store to develop the app jointly; we're supplying the technical expertise, and they're supplying years of experience of running a real, live registry.
Shoot me an email at adam@bencrudo.com if you're interested, we may be able to give you early beta access to the product.
Adam