Create a #date_field helper in your Rails form builder. It is essentially #text_field, but I ended up using this a lot.

Rails: ActionView::Helpers::FormBuilder#date_field

module ActionView
  module Helpers
    class FormBuilder

      # Make a field whose class includes 'date' and whose value can be custom-formatted
      def date_field method, options={}
        date = self.object.send(method).to_date
        options[:value] = options.has_key?(:format) ? date.strftime(options[:format]) : date.to_s
        options[:class].is_a?(String) ? options[:class] += ' date' : options[:class] = 'date'
      rescue
        text_field method, options
      end

    end
  end
end