Piston appears to have emerged as the preferred method for giving your Django applications a RESTful API. While there are any number interesting things you might want to want to do with such an API, this post is about using it to give your Django app an attractive, Ajax-y, Ext JS interface.
A REST-based system for building web applications.
A mini-framework for Django for creating RESTful APIs.
Introductory chapter from the O'Reilly book.
Note: "It would be easy for us to turn this into a formal specification but it is so easy to do with HTTP that there does not seem much point."
"Why build a RESTful web service for DayTrader? Because I frequently hear that REST can't be applied to complex situations."