Quick thought: the Smithsonian needs to hold quicker, shorter, and cheaper versions of this on a regular basis, think Foo Camp, Bar Camp, etc.!
Get 10 or so highly connected social networkers at the Smithsonian for a few days and have SI staff to the “Web & New Media Fair” to expose them to our cool projects. Grab those highly networked people in various specialities and let them loose to Twitter, blog, and get leverage of people with vast 2nd and 3rd degree connections (go play with Twinfluence: http://twinfluence.com/)
(photo above: Clay Shirky infront of the Smithsonian Flickr Commons tag cloud)