HABTM Question w/ checkboxes

Hello,
I have an address table that has a HABTM relationship w/ a preferences table. I want to set the preferences table to handle a variety of preferences for each address. For instance, for each address the preferences table could carry values for make_private = t/f, report_updates=t/f ect.

In my view where I set each value I have this code:

Code:
 <% @addresses.each_with_index do |address, index| %>
              <tr class="<%=cycle('odd', 'even') %>">
                <td width="10">
                <%=check_box("address", address.id, address.has_update_preference?(address.id)=='1' ? {:checked=>'checked'} : {:checked => ''}) %>
              </tr>
            <% end if @addresses -%>
and in my controller, I have this method that handles the updates of the preferences:

Code:
 def save_preferences
    unless params[:address].nil?
      params[:address].each do |key,val|
        pref = Preferences.find(:first,:conditions=>["address_id=? && preference_name='notify_update'",key])
        if pref.nil?
          pref = Preferences.new(:address_id =>key, :preference_name=>'notify_update', :preference_value => val)
          pref.save
        else
          pref.update_attributes(:address_id =>key, :preference_name=>'notify_update', :preference_value => val)
        end
      end
    end
  end
and in my model I have this method for populating each checkbox:

Code:
def has_update_preference?(id)
  update_preference = Preferences.find(:first, :select=>["preference_value"],:conditions=>["preference_name='notify_update' && address_id=?", id])
  unless update_preference.nil?
    return update_preference[:preference_value]
  else
    return 0;
  end
end

That's a lot of database calls for each checkbox, it seems rails would have a more glorious way of doing this.

I would also like to extend this address preferences concept to handle preferences on individual address fields
IE address.email = preferences.email_public_private t/f

Any suggestions?
Thanks,
Eric