gistfile1.rb

def stub_find_for_specific_values(model, stubs)
  model.stub!(:find).at_least(1).and_return do |id|
    if stubs.has_key? id
      stubs[id]
    else
      model.find_by_id(id)
    end
  end
end

#example below will return the mock_user if its id is search for otherwise find will search as normal
mock_user = mock_model(User)
stub_find_for_specific_values(User, mock_user.id => mock_user)