Simplicity in Web services has become the mantra for developer and author Bruce Tate, who is now pushing REST and Ruby on Rails for speedier, more reliable development. He argues the WS-* approach to Web services has created too many APIs for easy integration. In particular he thinks RoR will lead a lot of developers to consider REST practices.
Specifically Ruby on Rails has a very clean, very productive approach for building REST-based Web services. I would say you can do it with a quarter of the effort of a traditional Java Web service.