Switch python distributions
You need to update your PATH so that the stuff from MacPorts is in front of the standard system directories, e.g., export PATH=/opt/local/bin:/opt/local/sbin:/opt/local/Library/Frameworks/Python.framework/Versions/Current/bin/:$PATH.
UPDATE: Pay special attention to the fact that /opt/local/Library/Frameworks/Python.framework/Versions/Current/bin is in front of your old PATH value.
I have a MacBook Pro with Snow Leopard, and the Python 2.6 distribution that comes standard.  Numpy does not work properly on it.  Loadtxt gives errors of the filename being too long, and getfromtxt does not work at all (no object in module error).  So then I tried downloading the py26-numpy port on MacPorts.  Of course when I use python, it defaults the mac distribution.  How can I switch it to use the latest and greatest from MacPorts.  This seems so much simpler than building all the tools I need from source...
Thanks!