Trying to work around the two major parties in the US is a fools errand. The grassroots effort of Occupy should be directed at informing workers where their interests lie and organizing them to change the government.
The Democrats under FDR used to represent middle and lower class workers. Since the advent of the DLC and the Clinton administration, the Democrats have moved into Republican territory by accepting Wall Street influence. That is not their natural constituency. They have been able to do it only with the help of the main stream media, which is driven by money. The great mass of the electorate resides in the middle and lower classes. Now they rely mainly on the main stream media for their information, which is selling them a bill of goods on behalf of the 1% and the Washington consensus. To organize them around their real interests requires a door to door and internet media campaign to take over the Democratic Party and move it back to where it was under FDR.
The Republican Party is in disarray, and there is already a strong progressive element in the Democratic Party that is for reducing inequality, single payer health care, minority rights, environmental protection, a safety net, and a place for government in the economic landscape. People like Bernie Sanders and Elizabeth Warren are examples of the type of people that can be elected to national office. People like them can be recruited to local and state offices. The only problem now is voter reliance on the mainstream media and the political advertising propaganda it presents. A sustained grass roots effort on a personal level can turn that around. It's just a matter of personal contact to educate workers where there interests lie. This is the only way to overpower money in politics.
The demonstrations in the seventies around civil rights and the Vietnam war were ruthlessly handled by police and the military, which do what the government tells them to do. The same happened to the current Occupy movements in New York and elsewhere. The only way to give the middle and lower class workers a voice is to inform them of their real interests and organize them to change the government.