If you missed RailsConf 2006, you'll be glad to know that videos of the keynote presentations are being made available for online viewing and (coming soon) download. A collection of slides synchronized with recorded audio for all presentations will also be available soon. Videos and information about audio and slides can be found at ScribeMedia at the RailsConf 2006 Keynote Series page.
The first two keynotes by Dave Thomas and Martin Fowler are already available. The other five will trickle out over the next few weeks. Next up, David Heinemeier Hansson's keynote on "A World of Resources".