Wouldn't you also need "free hardware" to avoid the risk of your device being used against you? If you're not willing to trust the software on your phone, why would you trust that there isn't a tracking device built directly into the chips on the phone?
Given the way GSM works you'd also need 'Free cell towers', 'Free GSNs' and a 'Free network'. Not that I even know how that would be possible. You'd also still need 'Free airwaves' because you can triangulate from your own broadcast signal in some cases.
Which is untrue. I just purchased a Genesi Smartbook, which uses u-Boot and wasn't designed in a fascist country with a penchant for electronic espionage.