What Is PackageManager?
Since Python 2.3, MacPython has included the /PackageManager application. Though /PackageManager is still in its early stages, it's a huge time saver for acquiring Python modules and extensions that are tested (or modified) to work with OS X. The majority of modules in a /PackageManagerRepository can be installed precompiled with a single click.
How Do I Use PackageManager?
With an normal installation of MacPython 2.3, /PackageManager is located at /ApplicationsMacPython-2.3/PackageManager.app. By default, it will point to the official PackageManagerRepository, maintained by JackJansen. You may choose an alternate /PackageManagerRepository by choosing Open URL from the File menu.
Where Are The Alternate Package Manager Repositories?
So far, there is only one known alternate /PackageManagerRepository for OS X (or any platform, for that matter). This "Official Unofficial" /PackageManagerRepository is maintained by BobIppolito, and you can find instructions and an up to date package list at http://undefined.org/python/pimp/. It includes many more modules than the official /PackageManagerRepository inluding some compiled in exotic ways (such as Numeric against Apple's vecLib, or PIL with the libtiff patch).