Links - Web Service Design Patterns
The main link is part of O'Reilly Publsihing's ever-widening archipelego of XML sites - many of the articles are not related to web service design patterns per se. Sometimes one gets the impression that the real purpose of design patterns is to sell books about design patterns, but they are very useful nevertheless.
An excellent introduction to 'web service design patterns' is provided by Massimiliano Bigatti's articles Web Services Integration Patterns, Part 1 and and Web Services Integration Patterns, Part 2. They are dated June 30, 2004, but are far from outdated.
Although Java is not Open Source, Sun Systems's Core J2EE Patterns are reusable for Open Source applications.
Also notable is IBM's four-part series of articles on web service design patterns ( see related links ). There's an example of an actual, real-life SOA application - it's downloadable and runnable.