What's the simplest cross-platform way to pop up graphical dialogs in Python?

Question

I want the simplest possible way to pop up simple dialogs in Python scripts. Ideally, the solution would:

• Work on Windows, OS X, Gnome, KDE
• Look like

Answer 1

To extend on endolith's tkMessageBox answer with the ugly empty window in the background...

The code below pops up the box without the background window.

import Tkinter, tkMessageBox
root = Tkinter.Tk()
root.withdraw()
tkMessageBox.showinfo("my dialog title", "my dialog message")

This is lifted directly from a useful comment I found at the bottom of this article. Thanks to Jason (the commenter) and effbot.org.