If, like me, you don't like big cumbersome javascript files, and you'd rather load only the javascript you need right this minute, this little hack might help you.

In application_helper.rb : # local javascript for a certain page; this will only appear if this tag is called

      def use_local_javascript(local_javascript)
        content_for :local_javascript do
          javascript_include_tag local_javascript
        end
      end
      

Then, in the

<head/>
      

in your layout, you put the following:

<%=yield :local_javascript %>
      

Instead of multiplying layouts, you just call the helper on top of your pages, say:

<% use_local_javascript("just_magic.js") %>
      

(needless to say 'just_magic.js' should exist in /public/javascripts/

It's not nuclear science, but it allows you to split your javascript into small manageable bits, and include it only when you need, without multiplying layouts.

Update: in the meantime, there's :javascripts and :stylesheets defined for you by rails, so this code is no longer needed - but a different variant allows you to put actual scripts in the head, like when you want to define a variable.