I've never had any problems putting a research-grade python setup on OSX - just use the .dmg installer files files available for python (2.6.X for compatibility), numpy, scipy, and matplotlib. But I agree that the Enthought Python Distro is also a good alternative (if a little bloated for my needs), and it's also free for academics.
When I tried to use easy_install with the EPD it tried to take me to their repository, for which we don't have appropriate permissions? So I sucked it up and installed some from .dmg's and others from source (matplotlib was difficult). And I found out just because it's Python doesn't mean it's portable - for instance NumPy/SciPy is hardly ever installed on other machines (it's not trivial, as is written here many times), and I find that administrators won't update their Python installation so I've had to re-write bits of my code to accommodate Python 2.3-2.4 at times! But all said, it's a nice tool and hopefully these installation/ version issues will work itself out.
