gistfile1.rb

class Person
  include MongoMapper::Document
end

class Registree < Person
  key :in_wels,   Boolean
  key :in_vienna, Boolean
end

class Visitor
  QUERY = { "$or" => [{:in_wels => true}, {:in_vienna => true}] }
  
  def self.find(*args)
    Array(Registree.where(QUERY).find(*args).all).map do |registree|
      self.new(registree)
    end
  end
  
  instance_methods.each do |m|
    undef_method m unless m =~ /(^__|^object_id$)/
  end
  
  attr_accessor :real
  
  def initialize(*args)
    if args[0].is_a? Registree
      @real = args[0]
    else    
      @real = Registree.new(*args)
    end
    super()
  end
  
  protected
  
    def method_missing(method, *args, &block)
      real.send(method, *args, &block)
    end
end