A new tutorial over on the IBM developerWorks site (from Vikram Vaswani) shows how to pull data from the Google Notebook service into your script via the service's REST API.

Google Notebook is a free service that allows users to save and share notes and Web clippings in an online journal. A REST-based API allows developers to build customized PHP applications around this service using SimpleXML. In this article, you learn how to use the API, with examples of reading notebooks and notebook contents using PHP.

His method grabs the contents of the REST request and drops them into a SimpleXML object for easy manipulation. Different kinds of requests are included - getting the list of notebooks, getting the notebook's contents and how to add on extra parameters to the REST call to get more information in the responses.