I am in the middle of working with our user group on getting the groundswell ignited from users that attend the event. The main objectives are to get the vast majority that are consumers to just take a look at the blogs that will be covering the event (our corp blog, the user group’s blog and a few user blogs that we know of and will find out about during a blogger meet-up at the event) as well as perhaps start a twitter account to get updates, perhaps even on their mobile phones. We are also trying to get the smaller group that will actually create and share content to use a tag on all of their content (pics on Flickr, vids on Youtube, slides on Slideshare.net, tweets and blog posts) so we can more easily find it and roll it up.
Below is a quick first pass at how I see this working. Any ideas on how to make this simple for the majority and powerful for the minority are welcome (click for full size. I used Mind Manager by MindJet to throw this version together):