Old is new again. Using HTTP's basic vocabulary (GET, POST, PUT, DELETE) to define web services seems to be the big thing now. So JAX-RS and the Jersey implementation seem like reasonable sources for blog topics.

JAX-RS is the Java API for RESTful Web Services. This API is defined by JSR 311 (Java Specification Request), the official specification. Jersey is Sun's implementation of the specification. Jersey recently hit version 1.0, and you can download it now.