Nice work and great analysis! Here is another view of the fake accounts:
http://i.imgur.com/kFBHd9t.jpg

We can clearly see, from bottom to top:
- (Bottom) 6 account which have paid for fake followers.
- (Middle) A pool of 20+ unassigned fake accounts, ready to be bought I presume.
- (Middle) Oddly, bridges from those unassigned accounts to the real network.
- (Top) The legitimate twitter network, which looks a lot more 'organic'.

This was generated automatically with our in-browser graph exploration tool (graphistry.com). It connects to a GPU farm to do the heavy lifting and leaves only rendering for the browser. That let us scale to 1000x more nodes. We are hoping to release a public beta soon, email me at info@graphistry.com if you'd like to give it a spin beforehand.