Hadley Wickham, creator of ggplot2, has posted a 2 hour video on data visualization using R. You can find links to the videos and slides over at Revolutions Blog.
Check back here soon. I am working with Hadley to arrange a day-long ggplot2 short course here at Vanderbilt this summer. I'll post the date and registration info once everything is set up.
Video: Hadley Wickham gives a short course on graphics with R (via Revolutions)