For all the folks that are performing citizen journalism or witnessing duty at the New York Occupy Wall Street site this is a guide from the Citizen Media Law Project on what are your rights and responsibilities on covering the action in the community.
As the post explains, this is New York City specific but it will give you the legal information you will need should some one in a blue or white police outfit wants to have a talk with you or your recording device.
I keep saying it but be safe, be careful and when possible maintain distance from three or more officers.
What can I say? I'm skittish about mace.