I was fiddling around with easier ways to run python scripts in the Windows shell. I'll represent these as hypothetical AUTOEXEC.BAT entries (I used the UI for this):

;Add python to the search path so "python script.py" works
set path="%path%;C:\Python27"
;Add .py to the executable list so "script.py" works
set pathext="%pathext%;.PY"
;And finally (I couldn't find any other way) "script" works
set .py=python.exe

I think it would be a good idea to do this on installation. Any improvements and actual implementations using the registry would be greatly appreciated (especially since autoexec.bat isn't used anymore).