gistfile1.rb

class Application < Merb::Controller
before :check_remember_me
  
  def check_remember_me
    unless session.authenticated?
      if cookies[:auth_token]
        if user = User.first(:auth_token=>cookies[:auth_token])
          if user.valid_token?
            session.user = user
          end
        else
          cookies.delete(:auth_token)
        end
      end
    end
  end
end

gistfile2.rb

  class Merb::Authentication
    
    def abandon!
      Merb::logger.debug("Abondoning the authentication!")
      if session.user
        session.user.auth_token = nil
        session.user.token_expires_on = Time.new() - 86400 * 14
        session.user.save()
      end
      @user = nil
      session.clear
    end
  end

gistfile3.rb

Merb::Authentication.after_authentication do |user,request,params|
  if params["remember_me"].to_i == 1
    token = user.make_token
    request.cookies.set_cookie(:auth_token,user.auth_token,{:expires=>user.token_expires_on.to_time})
  end
  user
end