Great to see a curated collection of resources about RESTful practices. Hosted on code.google.com... now if only Google would uniformly adopt REST for their own APIs. Google is still using SOAP for the AdWords API and I get hives every time I have to dive into it.

Martin Fowler has a good article on the maturity levels of a REST API: http://martinfowler.com/articles/richardsonMaturityModel.htm...

That article provides useful ideas and targets for developing a REST API. Recommended.