Make most of your yaml files

When I first started with Ruby on Rails, the only purpose of yml files for me was using it database.yml files.

However when I started to work more on rails, I found that yml files can be more than just a database configuration file.

I started to use it more and more..like..

• Using it for translations, yeah I know people have been using this for while, setting up the locale and picking up the right one based on the language you selected. 
• Use it for storing some data, like you want to store list of all the countries(the easiest example I can think of right now), do it a yaml files. Why to store it in a database and fire an extra query?
• Try creating a form based on yaml, yes one of my friend did it and it was amazing.
• Storing some temp reports? Try saving rails best practices result for an instance? 

These are the just fews I can think of right now, I know there are many. 

You know of some, please feel free to share !!