Hot on the heels of Ruby on Rails (a very fast development framework for web/db based applications), Trails is a Java development framework in the same vein which allows for rapid domain based Java development.
The framework promises to allow developers to concentrate on the domain model and the logic, and then generates all the necessary plumbing code and wires it together using other frameworks such as Tapestry, Spring and Hibernate.
They have a demonstration video walking through the steps available on their site.