Rollback Python2.7 Installation
OS python scripts will use the default as the scripts look for /usr/bin/python not the one on the path.

If you want python at the command prompt to use 2.6 I would remove /Library/Frameworks/Python.framework/Versions/2.7/bin/ from the path.

To get the bare 2.7 python you will need to use the full path.

If virtualenv is not installed for 2.7 you need easy_install - which should be in /Library/Frameworks/Python.framework/Versions/2.7/bin /Library/Frameworks/Python.framework/Versions/2.7/bin/easy_install virtualenv(if that is not there you should add distribute or setuptools.)

To create a 2/7 vitualenv run /Library/Frameworks/Python.framework/Versions/2.7/bin/python virtualenv.py ENV then running ENV/bin/python gives you the 2.7 version - as would running the activate script to add the virtualenv python to the from of your path for the rest of the Terminal session.