I've used easy_install to get one or two modules, then I used pip to install the Twitter module.
However the newer version of Python I downloaded can't see these modules, only the built in OSX version can.
Also, I am now unable to download NLTK which I need for some examples I'm working through on a really good book called "Mining the Social Web".
Any thoughts?
Install the packages with the binary from your version of python.
So for example if your version is in /usr/local/bin then installing would be either:

/usr/local/bin/python setup.py ...
/usr/local/bin/easy_install  ...
/usr/local/bin/pip install ...
Install Python modules on new Python version