I just found Your Web Service Might Not Be RESTful If… by Paul Sadauskas. This article is a very clear and concise explanation of how to do real RESTful services.

His arguments are:

1. Present a single top-level resource;
2. All resources should be accessible by followling links from the top-level resource;
3. Don’t put API tokens in the URL or headers (use representations instead).

A very enjoyable read, and something we should all be following.