Forum OpenACS Q&A: Web API for photo printing
An imaging industry group call I3A announced the Common Picture Exchange Environment (CPXe) for moving photos between cameras and online storage/printing services.
Its pretty new, so I wouldn't rush out and write a service contract for it necessarily, but it looks like it's got some steam. Also, its not clear whether you have to be a company (pay $$$) to play with their network. It would certainly be a shame if that were the case.