This [StackOverflow question](http://stackoverflow.com/questions/671118/what-exactly-is-restful-programming?rq=1) has some good stuff about all this. But it looks like the gist of it is that POST shouldn't be passed an ID because the server gets to decide where to put it, you are just telling it to add the passed in resource. PUT on the other hand is telling the server to update a specific entity to match the passed in resource, so it wants the url to contain which object is being updated.