Connections among the Twitter users who recently mentioned #MWA2010 when queried on September 29, 2010 scaled by numbers of followers.
A list of top betweenness users is here: www.flickr.com/photos/marc_smith/5036510984/
The Mobile Web Africa 2010 conference was held in Johannesburg, South Africa on September 29 and 30, 2010
NodeXL is available from www.codeplex.com/nodexl
The book, Analyzing social media networks with NodeXL: Insights from a connected world, is available from Morgan Kaufmann and from Amazon.