The concept of sharing half of one's resources with others for good causes might also be appropriate for those people having assets in nine, eight or even seven figures. Now that the cachet of the wealthiest people sharing a good portion of their fortunes to benefit society has caught on, why not extend giving more widely?
The Foundation Center could establish a national register of very wealthy donors divided by regions or states or other categories. Similar pledges could also be encouraged from wealthy people all over the world.
The major benefit of this campaign would be to encourage people to enrich their lives by pondering how to help others in a big way. They would not be legally bound to actually give half of their assets while alive, but they would signal that they really want to contribute to other people and society in a significant way.