Newbie question: python versions differ per user?

[BobAalsma]

I'm on Mac OS X 10.5.8 and downloaded 2.6.4 Mac Installer Disk Image
as/in(?) the sys admin user. For this user Pyhton 2.6.4 is now the
current version.
I want to use Python outside the sys asdmin user. However, all other
users still use Python 2.5.1 (Apple delivered).

The sys admin user looks in /Library/Frameworks/Python.framework/
Versions/2.6/lib/...
The other users look in        /System/Library/Frameworks/
Python.framework/Version/2.5/lib/...

I could not find any questions on this matter, so am I the only one?
Did I do something wrong?
I assumed the paths for all users would be modified - too easy?