Nested Layouts

You can use partials to reuse chunks of html across different layouts.
For example, in your layouts directory could be setup like this:

/layouts/_meta.rhtml
/layouts/_nav.rhtml
/layouts/_footer.rhtml
/layouts/layout1.rhtml
/layouts/layout2.rhtml
/layouts/layout3.rhtml

In each of the three layout files, you'd include each of the partials
in their appropriate location in the page. e.g. to include the meta
info, you'd use <% render :partial => '/layouts/meta' %>

To specify which layout you're using in a given controller, just use

layout 'layout2'

at the top of your controller.

Hope this helps.