Modules are registered through ObjectMapper, like so:
ObjectMapper mapper = new ObjectMapper(); mapper.register(new JodaModule());
after which you can read JSON as Joda types, as well as write Joda values as JSON. It's really that simple; convenient and efficient.
Note that core Jackson does offer some level of support for Joda types; but this module is planned to take over these responsibilities; and possibly so that Jackson 2.0 might not have any Joda dependencies.
Just getting started...