The audio archives for the Accelerating Change 2005 are now available from IT Conversations (all 25 sessions for $25 via PayPal), and will be published for free on the site at a rate of about one per week.. (They also have an RSS feed).
Update 10/30/2005: Podcasts for the Accelerating Change 2005 talks by both Ray Kurzweil and Vernor Vinge are now available as free Podcast downloads.