Something came to my mind when Thomas mentioned the amount of users he has.
Its a minor thing for me but I think its worth suggesting.
When in the Admin -> Groups, you have to scroll down a (possibly) large list
of users to find who is a member. Hows about having a 2 box layout. One of
available users and the other showing current group members. Much like the
search pop-up window in calendar when you want to view multiple users.
Except no pop-up just the 2 boxes.
When Thomas wrote that he had 3500 accounts, I was floored as to how much a
bear it could be to scroll down the list to look for high-lited users. And
then to make a mistake and not hold down the CTRL key when adding additional
users.
Jer