I would like to get feedback on others' opinions of best practice for how to implement a progress bar in Python's PyGTK.

The work that the progress bar was to represent was very significant computationally. Therefore, I wanted the work to be done in a separate process (thus giving the operating system the possibility to run it on a different core). I wanted to be able to start the work, and then continue to use the GUI for other tasks while waiting for the results.

I have seen many people asking this question indirectly, but I have not seen any concrete expert advice. I hope that by asking this question we will see a community's combined expertise. I have read the FAQ and I hope that "Programmers" is the right place to ask.