I’m catching up on some blog reading.  A great blog on REST, if you don’t read it already, is Subbu Allamaraju‘s (in my blog links too).  I like to call him Dr. REST.  Back in May he wrote about Richardson’s Maturity Model and how measuring your APIs against the model is the wrong thing to do (I think he’s followed it up with a presentation).  I can’t agree more.  What I like about this model (and other articles like it) is that I like to compare it to my own history of growing my understanding of REST.  IMO, what you should do these models and guidelines is read them, examine them, see if they spark any ideas for improving your application.  They just might improve your understanding of REST and why certain constraints are good.  Don’t try to fit your API to REST.  Let REST help you write a better API.  Don’t apply REST for the sake of REST.  This is primarily why I unplugged myself from the rest-discuss mailing list.  If you treated applying REST as a set of guidelines instead of a set of laws you were castigated for it.  Wrong approach.

Anyways, as usual, great blog Subbu.  BTW, you should check out his book too.