If this is something you're attending:

• Figure out the hashtag people are using to talk about the event on Twitter. Share what you're looking forward to, connect with people who are going, and start the conversation.
• Blog about the event, linking to the site and to other people who are talking about it. Connect with other people who are going.
• Take notes and share them on your blog. Link to your notes on Twitter. Send e-mail following up with contacts, including a link to your notes.

If this is something you're organizing:

• Pick a hashtag, promote it, and link to it on the conference webpage.
• Keep an eye out for people, tweets, and blog posts related to the conference. Link. Consider using hashtags.org
• Consider asking for blogging volunteers. Link to their work.