Yesterday, I sent a draft proposal for a RESTful API out for comment. It pulls together a lot of the things I've been working on lately: OAuth, batching, and patching. It also has a different take on JSON vs. Atom data formats. Since OpenSocial has several different kinds of data -- activities, people, and app data to start with -- a one-size-fits-all format is likely to be a poor fit for everybody. So, there's a custom mapping, expressed through metadata, that can be different for each kind of data you deal with.