After watching Geoffrey Grosenbach's latest episode of Peepcode, a pay-for screencast series showing you how to do cool stuff with Ruby on Rails, I can safely say Restful Rails is the best $9 you could spend on Rails knowledge right now. Almost 90 minutes of screencast bliss packed with info is a steal, especially since you'll save so much time playing about.

It covers REST (Representational State Transfer), a concept, in Rails at least, where your models and data rule the roost. URLs are accessed with differing HTTP verbs depending on the action (GET to get data, POST to create data, etc) and data can be returned in different formats (HTML, XML, sometimes RSS) on the fly. REST is big news in the Rails world and will make up a big part of the de-facto way to develop applications with the Rails 1.2. Geoffrey's video takes you from total novice to expert in dealing with REST on Rails.

One thing Geoffrey doesn't mention is that not only do you get the video but in the archive you get all the code he develops during the video too! This makes it even more valuable. Hats off to Geoffrey for his great work and let's encourage him to keep making these videos so we'll see some even better ones in future.

(Still not convinced? Check out his free, groovy REST PDF cheatsheet.)