py2exe for deploying a Windows standalone GUI cross-platform (under Linux, all the python libs are available on the Linux hosts). You run the py2exe "setup" to build an .exe+, and py2exe pulls the binary bits and your python code and builds into a loadable, runnable Windows executable pack.
Python 2.5 on windows was the long-time requirement, but the recent 0.6.9 release added python2.6 (and python2.7?) support. No python3 yet.
Also, you may want to consult Py2exeAndPyQt on py2exe wiki.