I'm a huge fan of CouchDB, but I think that CouchDB is the answer to his problem just as much as using some other database like Postgres is the problem to begin

I'm a huge fan of CouchDB, but I think that CouchDB is the answer to his problem just as much as using some other database like Postgres is the problem to begin with. The problem with "REST" (oh yeah, baby, I'm getting the air quotes out) APIs to begin with is most of the time we heavily couple them to the fact that they will be consumed by a browser client. Design your REST APIs to stand by themselves and design them to be consumed by any client. There is no doubt that web browsers have special needs, address those special needs with a (hopefully) thin layer between your REST API and the browser.