A few days ago I released RESTNotes. RESTNotes is a code sample package of a distributed notes application. It consists of an iPhone application that stores all its data in an WebObjects server app. Communication is done using REST style techniques.
I’ve done this to learn about REST, and get the feeling of how should things be made, what problems would I find, and so on. I spent some time creating an easy-to-use methodology on the iPhone side, making the communication APIs simple but flexible. Also, I looked at problems like authentication and error reporting.
If you’re interested, the source is published on Google Code, together with some nice documentation on the project wiki, explaining the general architecture of the client and solutions to some of the problems I found. Hope you find it useful. :)