Where to put partials shared by the whole application in Rails?

The Rails convention is to put shared partials in /app/views/shared.

Update

Layout inheritance is now in the guides under layout and rendering Template inheritance works similarly.

Rails 3.1 and following versions implement template inheritance, so I think the correct place for shared partials is now /app/views/application/, say you are in products#index you can do the following:

-# products#index
= render @products.presence || 'empty'

-# /app/views/application/_empty.html.haml
There are no items

btw it's application because the connection is the controller inheritance, so this assumes ProductsController < ApplicationController

This way if you implement /app/views/products/_empty.html.haml that will be taken, the above is a fallback for all the missing partials, and I can't check right now, but I think even for the template itself...

Railscast: template inheritance!