[Findeton]

Or you could simply use Linux.

[josefx]

Use Linux and blacklist any package that calls home. Ubuntus Amazon search integration wont be the only black sheep out there.

[Piskvorrr]

Or better, if you're worried about PCI compliance - start with a minimal system and whitelist specific packages that do not call home. Does that computer actually need all that software that comes with a default install? (Most likely not)