Teach Yourself Web Services in 3 Minutes™

Artima has a good article on JSR-224, AKA JAX-RPC 2.0. That is a whole bunch of unfortunate alphanumerics that simply mean SOAP services in Java. JAX-RPC 2.0 is based on JDK1.5 annotations to simplify deployment (by the way, I think you can count on "is based on JDK1.5 annotations to simplify deployment" to be a running theme for all the Java server related technologies for the next couple years.