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."