Mason Browne just released Bricklayer, a simple way of creating your ruby library for a REST webservice. It walks you through the twitter example ( Twitter is the Hello World of REST APIs!) and you get 22 lines of a complete Twitter API.
I’m really considering doing the same in Python, but taking a different approach, more like the Django Models, but for APIs. I believe with that much APIs available, we need a simple way of adapting to each, one of the problems WS-* have being pointing out to RESTafarians for a while now.