Topic: Store configuration/single values

I want to be able to change some standard values. It would be easy to put them in a constant but feel we need to experiment with the values a bit. So I want to easily change them in a form on the admin interface.
Im using Heroku.
Is database table with a single row I insert with the migration the best option? I feel it's a bit overkill and also it feel like a strong coupling with the code and data is a bad idea.

Re: Store configuration/single values

Im using:
https://github.com/huacnlee/rails-settings-cached

It works perfectly. If someone has any other suggestion im willing to take it into consideration.