Resources for Restful Authentication in Rails

I've been doing a fair bit of REST web service work in Rails apps lately. One of the interesting parts is doing the authentication pieces, and coordinating this with your regular interactive authentication. I've also been ramping up on the whole Simply Restful thing. I'm not totally sold on it, but the one thing that is definitely appealing about it is the further constraint it places on your code for which that primarily comes down to enforcing more consistency.

Anyway, in terms of REST WS API's, and authentication, there's a new Restful Authentication plugin that uses acts_as_authenticated. The San Diego ruby user's group had a video podcast and slides that touch on it briefly. These point to NAME's blog entry on using this for REST WS and authenticated feeds as well. Good stuff.