Been playing around with Drew Conway's scripts he demo'd at the bay area R meetup at linkedin last week - saw it here.
Files to do this yourself are here.
Information on the libraries: Igraph twitteR ggplot2
Installation (for OS X):
- Install latest Mac OS X R build 2.10
- Install latest tcltk
- In R, execute: install.packages("igraph"); install.packages("twitteR"); install.packages("ggplot2");
Have at :) Beware the API limit.
Oh, the MS zoomable thing.