There are a lot of complaints about number of groups in second life, at the same time second life is supposed to be about bringing groups of people together.
I propose there be some mechanism for marking inactive groups as inactive, a group should be inactive if there's no land deeded to it and no notice in the last two months (although what constitutes an inactive group is flexible, but fundamentally people don't want to join inactive groups, they certainly don't want to pay to join inactive groups, but inactive groups don't bring anyone together).
I'd actually like to see this used further, I would like there to be ticket requests to merge inactive groups into an active group on the same topic. Or for someone to ticket to take over an inactive group. But the first step to that would be marking inactive groups as inactive, and I think that alone would be useful when people search groups.