Stefan G. gave a nice demo of this at Buzzwords (http://gephi.org/) and I tried it out on the plane ride home and it seems like it could be used as a nice way to visualize clusters. It can import a CSV file that is essentially a big matrix of nodes and edges. I think it wouldn't be too hard to have a job that converts the clusters into this CSV format for easy loading. Just throwing it out there as food for thought.
-Grant
