Rails gem: What is the best way to keep all versions of database objects and to save changes linked to a user?

I have a collaborative app environment, where I need to store/log information on w开发者_开发知识库ho changes what in the system.

All versions of every object needs will be saved with user information, and no data can ever be deleted.

What should I look at besides extending vestal_versions?

http://ruby-toolbox.com/categories/activerecord_versioning.html

http://ruby-toolbox.com/categories/activerecord_user_stamping.html