Web services

Hi All and thanks for reading,

I have fought with management to get a listing of Active Directory groups so I can simply add them to the SharePoint environment but I was informed that I would have to add "individuals" to SharePoint groups! That is crazy! My question, what SharePoint Web Service can I use to get a listing of AD groups and run to also get a listing of who is that group?

I currently use "GetUserProfileByName" web service.

Thanks