The iPhone & Rails love at first sight

ObjectiveResource is a framework for the iPhone that makes interacting with Ruby on Rails applications dead simple.

ObjectiveResource is an Objective-C port of Ruby on Rails' ActiveResource. It provides a way to serialize objects to and from Rails' standard RESTful web-services (via XML or JSON) and handles much of the complexity involved with invoking web-services of any language from the iPhone.

http://www.iphoneonrails.com