Office Design

For a long time I have been trying to think of what the best layout is for offices on a programming team.
There are 3 basic approaches:
War Room
Cubicles
Private Offices
While each approach has its advantages and disadvantages, I think that which is best is a function of where you are in the development cycle.
As it turns out A development cycle has 3 basic parts:
Pre Alpha
Alpha To Beta
Beta To Ship
It would be interesting to try and develop a product where you used a different arrangement for each part of the cycle.
Pre Alpha -> War Room
Alpha To Beta -> Cubicles
Beta To Ship -> Private Offices
This would maximize communication during the initial conceptual phases but allow for privacy, peace and quiet during the end game where people pretty much know what to do but just need to be left to do it.
Its also an interesting way to set up an incentive. You get the nice private office when you achieve that milestone.