Mike (@mbostock) gave a talk at Trulia for the Data Visualization meetup group introducing D3, a visualization framework he made after his work on Protovis and Polymaps.
Apologies for the quality. Our video equipment died so Joe Golike (@golike) saved our asses by recording the talks on his phone.
Slides of the talk are here:
More information on the meetup here: http://meetup.com/VisualizeMyData/