JSON Annotating of Java Beans

As I was working through a GWT Code Serializer for generating Java serialization code to serialize objects as XML or JSON, I started thinking about how nice it was to leverage JPA Annotations in documenting JSON serialization on persistent beans. Wouldn't it be nice to serialize objects to JSON as easily as we can do with JAXB? After searching the WEB for a solution, I was almost about ready to go ahead and develop an Annotation infrastructure for this very problem. That was when I came across Flexjson, which does exactly this. In fact, unlike JAXB's marshalling terminology, Flexjson actually calls it serialization. As of yet, I have not tried Flexjson, but from looking at the examples shown in the link above, it seems to do exactly what one would expect.