Actually "[http://voidspace.org.uk/python/programs.shtml#movpy Movable Python]", a project of MichaelFoord. Michael gave [http://media26a.libsyn.com/podcasts/awaretek/Python411_060402_Fuzzyman.mp3?aXdueJh1mXmYdmx8bXhtpWasaHOZ an interview] on this and related subjects.
Movable Python itself "is a distribution of Python (for Windows) that doesn't need to be installed."