I am trying to figure out how to get effects to work on my MacBook, running OSX 10.4, Inkscape .45. I found the python_packages.dmg on http://inkscape.modevia.com/macosx-snap/, which is what seems to be the problem. I can't figure out how to add these packages to Inkscape because it does not have "PYTHON" directory in the Inkscape.app package >> Contents/Resources/. Could someone give me instructions on how to do this? I appreciate the help!
-Thanks!

It's been a while since I use OS X so this may be wrong. Inkscape places its python scripts and modules in its extension directory. This would one of:

/usr/share/inkscape/extensions/
/usr/local/share/inkscape/extensions/

If neither of these is on your machine, search for the inkscape directory:

find /usr -name inkscape

You should find an "extensions" subdirectory.

Thanks for your reply. It was actually my fault: http://inkscape.modevia.com/macosx-snap/ says to install a newer built of inkscape if you cant find the python folder in inkscape.app. The inkscape.dmg which is available on inkscape.com homepage is not as new as the ones available on http://inkscape.modevia.com/macosx-snap/. When I installed the newer inkscape, I found the python folder under Inkscape.app and copied the python packages there. Now it works perfectly!