Setting a Ringtone for my groups

Good day
Is there a way to have a Group of friends (AKA people from work) to all have the same ring tone? and not having to change it for all my friends.
I add/remove contacts everyday. I would like to have setup so that anyone that I place in the group work rings one way and all the people in Friends rings some other way and so forth and so forth.
does anyone know I was of doing this?
because i cant find a way to do it in Itunes Mac I'm on 3.0
cheers

 

anyone????