Creating dynamic pages in Ruby on Rails

What is the best solution for creating dynamic pages in Rails? I am working on a simple admin interface where I want to be able to create content pages and dynamically add them to the site without adding them to the controller.

That is, you do not need to do this in page controllers.

def about
...
end

def privacy
...
end

I was thinking of doing something like that all pages use the show action, which looks at the url by permalink and database selections, although I'm not sure what the best approach is. Any feedback on this would be great.