is it possible to create python executable targeted for linux, from mac os x?
PyInstaller seems to be at an early stage, and I don't know much else.
There is tool that can be run on single OS and make you executables for different OSes. You will need to do the compilation for every OS on a (virtual)machine that have it installed. Fox OS X you can check py2app in http://undefined.org/python/
Do you really need a standalone executable? For most Linux distributions, the easier and more common way to distribute Python software is to just distribute the source.
Every major Linux distribution already has Python installed, and some have it installed by default.
Dont know if available for OS X but take a look at cx_freeze