REST handles service discovery very differently than traditional approaches like SOA. With SOA, deployments centrally manage service metadata in repositories. To discover a service, access the metadata in the repository. With REST, however, each representation contains all the metadata you need (the self-descriptive messages constraint). To discover a RESTful service, follow the appropriate hyperlink.
Read the entire post at http://www.devx.com/blog/restful-service-discovery.html.