# File flickr.rb, line 112
  def users(lookup=nil)
    if(lookup)
      user = people_findByEmail('find_email'=>lookup)['user'] rescue people_findByUsername('username'=>lookup)['user']
      return User.new(user['nsid'])
    else
      return people_getOnlineList['online']['user'].collect { |person| User.new(person['nsid']) }
    end
  end