New from PHPBuilder.com today is a new article - An introduction to web services with PHP. In this article they give you the basics using as the example a few calls to the Google Web API.

Have you ever wanted to enrich your site with information from Google, Amazon, eBay, or one of the many other sites that provide web services through SOAP? In this tutorial, I will be demonstrating how to use the SOAP package from PEAR to query Google's extensive database (consuming the web service, in the jargon). This tutorial assumes you are using PHP 4 and PEAR::SOAP 0.8.1, and requires basic familiarity with PHP (including a little object-oriented programming).

They step you through the process, showing you how to install the PEAR SOAP package, getting an API key from Google, and, of course, the call to the API - a spell-check example.