Install Python to match directory layout in OS X 10.5
Personally, I wouldn't worry about it until you see a problem.  Messing with the default python install on a *Nix system can cause more trouble than it's worth.  I can say from personal experience that you never truly understand what python has done for the nix world until you have a problem with it.
You can also add a second python installation, but that also causes more problems than it's worth IMO.
So I suppose the best question to start out with would be why exactly do you want to use the 64 bit version of python?
The default Python install on OS X 10.5 is 2.5.1 with a FAT 32 bit (Intel and PPC) client. I want to setup apache and mysql to run django. In the past, I have run Apache and MySQL to match this install in 32 bit mode (even stripping out the 64 bit stuff from Apache to make it work).
I want to upgrade Python to 64 bit. I am completely comfortable with compiling it from source with one caveat. How do I match the way that the default install is laid out? Especially, with regards to site-packages being in /Library/Python/2.5/ and not the one in buried at the top of the framework once I compile it.