Clear’s Privacy Policy is superb – they’ve got wiki-like markup showing the changes they’ve made.
Great example of information transparency.
By the way, my new venture, WordPress.com shared their own Privacy Policy under a Creative Commons licence. I’ve done the same with a ‘UKised’ derived policy for a new venture, a collaborative outliner, ThinkFold (I’ll talk more about ThinkFold later today, when we go into private beta :-)
(Via Esthr Dyson.)