Sometime ago i put some work into an ExpressionEngine Database Trace Module trying to solve the issues with local development environments and how to sync db changes to your live site.
The general concept is to trace your local changes and store them into a release file. Release files can be deployed through FTP/GIT/SVN/Etc, after deploy you can do an install of the release, pushing all your db changes.
Demo (sorry for my bad English): http://www.screenr.com/ZnmH
You can pull the code from here and give it a try: https://github.com/fccotech/ee-db-trace
Feel free to clone/fork/pull/push/comment.
The module works, but needs feedback and improvements. I would like to discuss this concept and try to push it to the next level