Portable Python from: http://www.portablepython.com/
Makes Python25 portable enough to run from a small USB flash drive. It comes with the very capable editor SciTE.exe preconfigured to run on portable Python. Simply run your Python code from SciTE (press the F5 key).
You can plug this USB flash drive into any Windows computer and it will run Python25. I installed (extracted the downloaded zip file) PortablePython1.0 onto a 512M USB flash drive I purchased for $3.00. Portable Python, wxPython, pygame, django and a fair number of sample files take up about 145M.
You can add the wxPython GUI toolkit to Portable Python by simply copying the wx directory from your normal Python25 installation for instance at:
to Portable Python for instance at: