FYI, this works out of the box with Mac OS X Lion's system Python and the gfortran compiler from homebrew - that's the only thing I need to install separately (Xcode and brew are required to install that, of course, but most people doing any sort of coding seem to have them anyway).
Also, a tip for those of you wanting to do the same:
I'm running IPython notebook, ggplot and all required packages under my user account without any hassles whatsoever thanks to this:
$ cat ~/.pydistutils.cfg
[install]
install_lib = ~/Library/Python/$py_version_short/site-packages
install_scripts = ~/Library/Python/$py_version_short/bin
install_data = ~/Library/Python/$py_version_short/share
Just set $PATH to include the install_scripts, run pip, and you're all set. Everything just works, without the need to install another Python interpreter or mess about with system components.
(edited for formatting)