The automatic build wont work on OSX. Download the tarball
http://easynews.dl.sourceforge.net/s...b-0.3.5.tar.gz
Extract the files. In the pyusb directory run the commands
python2.5 setup.py build
sudo python2.5 setup.py install
If that works could you use
http://cheeseshop.python.org/pypi/bdist_mpkg/
to create an mpkg that I can add to the wiki for other OSX users?