Flying Widgets adds CSS3 transitions to your dashboard, allowing you to cycle through multiple widget sets on a single TV without page reloads, using stylish CSS3 transitions. You can even still re-order your widgets and save their locations!
Note that sinatra-cyclist is a potential alternative if the machine you use to display your dashboards is lacking in graphics horsepower.
To use, put this file in assets/javascripts/cycleDashboard.coffee. Then find this line in application.coffee: