defining a global scope on a model


I've got a table sharing situation where Single Table Inheritance is
not viable.

I would like to be able to define a "scope" that is applied whenever I
am using that model to allow me to construct my relationships.

so far I have done this:

class SomeModel < ActiveRecord::Base
  scoped_methods << {
    :find => {:conditions => ['is_special = ?', false] }

class SomeSpecialModel < SomeModel
  set_table_name 'some_models'
  scoped_methods << {
    :find => {:conditions => ['is_special = ?', true] }

This actually satisfies my requirements... but I'm not happy about
using the undocumented array of "scoped_methods" for my purpose.....

Is there a more Railsy way of achieving this goal?

Any ideas welcome...except STI :slight_smile: