Make:

Sketching in Hardware 2, a summit on the design of/with physical computing toolkits, took place from June 23-24 2007 at the Mechanic's Institute Library in San Francisco:

The act of sketching defines and redefines boundaries. Everyone who makes sketches, whether on paper, in software or, increasingly, in hardware. Sketching may begin with an idea, but the process fundamentally changes that idea. Sketches identify both what an idea is, and what it is not. They serve as histories and illustrations. Sketching tools simultaneously help and constrain the possibilities of sketching. Make a new sketching tool and new boundaries appear, while old ones dissolve.

The Sketching pool on flickr is full of photos from the event (one of Julian Bleecker's CC-licensed photos is shown above), and you can download the presentations as well. [photos | presentations] - Link