"What ever you do, don't cross the streams"

Single stream or multistream recycling. This is the dilemma that municipalities deal with in the Hamlet of the Garbage dump, "to sort or not to sort" The San Francisco Chronicle has this article on composters struggling to make cleaner compost free of contaminants. How do you struggle to get people to sort their trash, sometowns have given up and just pay service to do it for them.

Is the solution instead to make sorting unnecessary? Can we come up with machines that do it? Or do we take the "Cradle to Cradle" approach where waste becomes the raw material for the next product?