Gloria W. - RESTful Thoughts on a Web 2.0 Python Project:

"It helps tremendously to work out the ‘chatter’ between the client and the server in human language before designing it. Here is an example of RESTful chatter between a client inventory application, and it’s corresponding server application: [...]

The point of the chatter is to ensure that the client is passing a complete transaction with every request, and that the server passes a complete transaction with every response. Similar to the CRC cards for OO design, the Chatter ensures that you have your states, transactions and interfaces well defined."