Any substitute for OG promote module in Drupal 6?

i never used og promote cause i started with d6, but i really wonder why nobody seems to need that function besides us two.
is it so uncommon to need specific roles for specific groups and feeling too lazy to do it manually?

anyway, i just found a very basic way which works with my system cause till now i only have one group ;)
try the rules module (http://drupal.org/project/rules) and there you can add a trigger (e.g. user subscribing/unsubscribing to group, user approved to group by admin) and give it an action (add user role/remove user role and after that select the role(s) you want to add)

there is also a possibility to add conditions to those rules, but i have really no idea how to use them (documentions, like most of the time, very poor).

cause i wasn´t able to restrict the action to a specific group, this rule would now apply to all groups by giving all users joining the same role(s). as i said, i only have one group so far, so no big problem for now.

the rules module really does a great job so far. i set up two rules, one for adding and one for removing the roles on the event of subscribing/unsubscribing

if someone has an idea how i could make a selection of the groups which should get the special roles added, please tell