gistfile1.rb

class CookieTestController < ApplicationController
  def set_cookie
    cookies.delete :hello
    cookies[:hello] = { :value => "Hello there at #{Time.now}!", :expires => 2.weeks.from_now }
    render :text => "cookie set to: #{cookies[:hello]}"
  end
  
  def view_cookie
    render :text => "Cookie: #{cookies[:hello]}"
  end
end

gistfile2.txt

GET /set_cookie

cookie set to: Hello there at Thu Mar 18 00:27:07 +0100 2010!

GET /view_cookie

Cookie: