Stephen Carlson is going to be tweeting SBL. I tweet all sorts, and then tweet even more when I'm at something of greater interest than just a visit to the pool, so I'll be doing the same. It looks like the hashtag to use is going to be #SBL Tweetup.
Update: Actually, it looks like #SBL Tweetup is specifically about finding a meet-up time for twitterers. Perhaps we should think of another hashtag for just tweeting the meeting. How about #SBL New Orleans?
Further update: It looks like #SBL09 is gaining in popularity.