I still consider myself primarily a programmer, despite spending most of my time working on Web sites. I've been using patterns to improve my software - mostly programs for the construction and maintenance of sites, but also traditional CGI programs and servlets - but have started thinking about the patterns involved in the design and construction of the sites themselves.
The applicability of patterns to Web sites struck me after the recent launch of the site for a local hospital. Not even a week later, we found another recently launched hospital site that shared the same structure. Looking at the two side-by-side, I was struck by the thought that the other site's team certainly experienced the same forces we did. It's not quite the RuleOfThree, but I'm positive I could find another example.
There's now a book that contains a pattern language for Web site design. The Design of Sites: Patterns, Principles, and Processes for Crafting a Customer-Centered Web Experience by Douglas K. van Duyne, James A. Landay, Jason I. Hong ISBN 020172149X . There's a companion Web site at http://www.thedesignofsites.com/. -- JohnBrewer