Ubufox is very clever at wrapping the Firefox extensions and add-ons feature with the Ubuntu package manager.
A similar thing should be done with Open Office extensions - so that installing an extension with the Open Office package manager integrates well with Ubuntu.
I agree, it is annoying having to install extra dictionaries through the ooo wizard, and not very user-friendly. In ubuntu most installation of programs, add-ons, plugins etc. should be handled by apt or aptitude.