Using two versions of Python

["Edward C. Jones" <edcjones@comcast.net>]

I have the package "python2.3_2.3.4+2.3.5c1-1_i386.deb" on my Debian sid 
system.  I also compiled the Python tarball. It is in "/usr/local".  I 
would like all of the code that I have written to use Python 2.4 without 
messing up all the Debian packages that use 2.3. My programs all contain 
"#! /usr/bin/env python".  I would prefer not to change them all. How 
can I do this?