Question: How do I point Blender to the version of python I have installed

Answer: 
Blender 2.5x now comes bundled with its own python, this is un-modified, only included to so users don't have to match their system versions of python.

If you remove this python/ directory blender will look for python on the system, matching the version it was compiled with. (3.2, 3.3 etc, minor point releases are all inter compatible).

If you want to point to a non-standard python path you can set PYTHONHOME environment variable - python documents how this works (nothing specific to blender).
Personally, I was setting my PATH environment variable so that Blender would find the most appropriate version of Python first.