This the audio and slides from the presentation Chris Fahey gave at SVA's Interaction Design Program series dot dot dot. In this excellent short short talks (16 minutes), Chris talks about sketching and shows plenty of examples from his notebooks. Great series of events that Liz Danzico and company are putting on. Chris will be on the faculty of the MFA program.
http://www.slideshare.net/askrom/talking-about-sketching-about-interacting-presentation/