Occupy Wall Street could actually use a demand that is straight-forward and would have broad support. Accomplishing this would give the OWS movement credibility and moral connectivity. The demand should be one that is concrete and would advance the OWS agenda while morally isolating its opponents. The best demand for this purpose would be:
A constitutional amendment that would eliminate any of the benefits of the Bill of Rights from accruing to corporations, and simply state that the rights enumerated in the Bill of Rights only accrue to natural born persons is exactly the kind of demand that OWS needs to make. It is a simple demand, and one that, if acted upon would dramatically change the political landscape by allowing all kinds of limits on corporations. Such an action is a precondition for dismantling incipient corporate fascism before it takes root.
Any one who opposed that would so clearly isolated themselves that they would be committing political suicide. Also, such an amendment would have concrete results, for example, overturning Citizens United.
I like the catchy name Demand Zero, too.