Here is some prescient advice he gave us nearly 40 years ago:
"We must rapidly begin the shift from a thing-oriented society to a person-oriented society. When machines and computers, profit motives and property rights are more important than people, the giant triplets of racism, militarism, and economic exploitation are incapable of being conquered. A nation can flounder as readily in the face of moral and spiritual bankruptcy as it can through financial bankruptcy."
That's from his speech entitled Beyond Vietnam, which he delivered in April of 1967. You can hear excerpts of other speeches in his own voice by clicking here (broadband and Flash necessary) and you may read the full transcript of Beyond Vietnam and hear additional excerpts of it here.
Another favorite (this one is a little unsettling in light of the current state of world affairs; spoken at Atlanta's Ebenezer Baptist Church also in 1967):
"Don't let anybody make you think that God chose America as his divine messianic force to be a sort of policeman for the whole world. God has a way of standing before the nations with judgment and it seems that I can hear God saying to America, 'You are too arrogant. If you don't change your ways, I will rise up and break the backbone of your power, and I will place it in the hands of a nation that doesn't even know my name.'"
If you have any favorite quotations of Dr. King, please post them in the comments.