Topic: Replacing local jQuery for CDN jQuery

Any tips for replacing a local copy of jQuery in Rails 3 to use Google's CDN version?

Should I just hard-code Google's script reference in my Application layout? Or does Rails 3 have some magic I should use instead?

I know in config/application.rb I can specify something like this:

config.action_view.javascript_expansions[:cdn] = %w(https://ajax.googleapis.com/ajax/libs/jquery/1.5.2/jquery.min.js rails)

But how do I use that, and how do I do the same for jQuery UI?

Basically, what is the best practice for using jQuery & jQuery UI CDN in Rails 3?