A quite short message to speak about Object Oriented Databases. OODB had a short success in the early 90ies but suffered of the lack of performances and of the dubts about the object paradigm. 15 years later, everyone develop with an object oriented language, or modelize with UML or such a formalism.
OODB have made a lot of progress in this laps of time, and are quite mature and efficient from now. I suggest you find out their capabilities and gains we can have not to use such frameworks like Hibernate or Ibatis to translate your domain objects into table fields... You handle only objects and it is convenient :)
I personnaly like DB4O, but many other OODB are very nice like Versant Object Database, InterSystems Caché, Gemstone, ...
I think it is time to reconsider the ways to develop distributed applications, communicating systems by trying to simplify the job of developpers by using less and less gateway technics.