Here is a simple SPA application, which utilizes Ruby on Rails 3.2.11 as data provider and Ember.js + jQuery Mobile for user interface. You can use that app as draft for creating your super Single Page App!
Checkout live demo: http://ember-rails.tbprojects.pl
In this example the SPA displays list of cats from http://www.lolcats.com website. User can change pages of results and load single bigger image. Ruby on Rails application fetches data from external source, parses it with Nokogiri and then responds with prepared JSON.
jQuery Mobile was used to introduce mobile friendly interface. Using Ember.js and jQuery Mobile together might be tricky, however following proof of concept helped me in preparing this example: https://github.com/LuisSala/emberjs-jqm