#ias09 is the twitter hashtag for the Summit. (Ironically, the official hashtag was IAS2009 but it never caught on because it was "too long" to type in repeatedly. Funny how the masses can overrule official decisions. I'm sure there's some analysis in that as well).
I went on to ManyEyes and uploaded some data. Here it is:
This represents all tweets with #ias09 from the beginning up until 3/25/09 that appear on twitterscan.com.
Is it comprehensive? I copied all #ias09 entries that showed up there.
Is it reliable? I don't know... is twitterscan reliable? Maybe the masses can comment on that.
Is it interesting? I think so! But I'm a data geek. For example. "@whitneyhess" is the most common term here. "@whitneyhess" means that her's was the most reffered to twitter handle associated with #IAS09. This is different from "whitneyhess", which would mean that she was the most frequent twitterer for #ias09. That honor goes to @bnunnally.

Even more interesting is that "whitneyhessing" is now a verb. As in "mediajunkie: @bnunnally Thanks for whitneyhessing this talk!..."
Here is some artwork from http://www.wordle.net. It's the same data, in a prettier format.

References:
Many Eyes - Data viz tool for the masses
http://www.wordle.com - word art
Information Architecture Summit