For a while now I've been flying the flag for using a post-redirect-get design pattern when writing web applications. In my opinion the current crop of web frameworks still make it very easy to do the "bad" thing since to do PRG properly you need to think what kind of an interaction you want with users and not cop out saying its technically very difficult in
Whenever I play with Rails, or for that matter any other web framework, I get stuck on trying to find a problem to solve (or a set of requirements). Fortunately the Agile Development with Rails book from the Pragmatic Programmers has a nice little bookstore application that I can develop iteratively. I've put my latest adaptation of their depot application to use post-redirect-get (even works with ActiveResource scaffolds), UUIDs as ActiveRecord primary keys, HAML, SASS and RSpec on GitHub. Feedback is always welcome.