Capital Commons Trusts
Described by Peter Barnes:
"A capital commons trust would be a giant mutual fund owned by all Americans on an equal basis. Publicly traded companies would contribute shares to the fund at the rate of 1 percent per year, up to a maximum of 10 percent of their shares. The contributions would be the price these companies pay for the socially created benefits of public liquidity -- a small price for the hefty benefits. (When a company "goes public," its stock leaps spectacularly because it can be sold instantly to anyone."
See the entry on Trusts for a full explanation.