Solid cross-platform threads support in GUIs: tkinter, pygtk, wxpython or pyqt

I have some experience with 开发者_如何学Cpygtk, and I feel very comfortable with, except when the threads are necessary on windows, so I was wondering, how does my fellows programmers deals with threads in tkinter, pyqt and wxpython in a cross-platform environment (or at least linux-windows)?.

I'll really appreciate sample threading code, with each toolkit.

For wxPython, check out the following links:

http://wiki.wxpython.org/LongRunningTasks

http://www.blog.pythonlibrary.org/2010/05/22/wxpython-and-threads/