Negotiating a Pay Cut?

csb asks: "My employer will probably ask me to take a pay cut in order to prevent (or at least minimize) layoffs. I want to keep this job; but, I don't know what to request in return for accepting a temporary reduction in salary. Is this a negotiation? What questions should I bring to the table? Which issues should I stand firm on, and what should I let slide? Are there some resources out there about this sort of thing?"