I have a problem of upgrading python from 2.4 to 2.6:
I have CentOS 5 (Full). It has python 2.4 living in /usr/lib/python2.4/ . Additional modules are living in /usr/lib/python2.4/site-packages/ . I've built python 2.6 from sources at /usr/local/lib/python2.6/  . I've set default python to python2.6 . Now old modules for 2.4 are out of pythonpath and are "lost". In particular, yum is broken ("no module named yum").
So what is the right way to migrate/install modules to python2.6?
Some Python libs may be still not accessible as with Python 2.6 site-packages is changed to dist-packages. 
The only way in that case is to do move all stuff generated in  site-packages (e.g. by make install) to dist-packages and create a sym-link.
Transition from Python2.4 to Python2.6 on CentOS, module migration problem