Greetings,
It would be great if there would be some way to compare the lists, especially and most specifically memberships -- to see how many members are held in common between some groups.
Look in View--> Statistics Builder.
You can do lots of comparitive tests on groups. However, you cannot tell which people are members of the same group. Thats a good test and one I shall add to the development queue.
Cheers,
Wilson.