Python cx_Freeze package
I've recently started using the cx_Freeze Python package. This package makes it possible to more easily distribute Python-based programs by packaging together all of the libraries, python modules and supporting files that are needed to run the program in a single, stand-alone, directory. The Python script itself is turned into an executable which can be run directly from the command line. And, unlike some alternative, this package works on Linux!
This package is therefore is great for distributing somewhat sophisticated Python programs to people who do not necessary know how to install supporting packages or compile required libraries. The Python library itself is packaged together with the script but the resulting package still requires a reasonably similar Libc in order to run on a different Linux release/distribution.
One word of warning though -- when installed using easy_install the package does not function correctly, so it is required to install directly from the tar-ball.