PythonCard is really easy to use. That's what I would recommend.
Here's their writeup:
PythonCard is a GUI construction kit
for building cross-platform desktop
applications on Windows, Mac OS X, and
Linux, using the Python language.
The PythonCard motto is "Simple things
should be simple and complex things
should be possible."
PythonCard is for you if you want to
develop graphical applications quickly
and easily with a minimum of effort
and coding. Apple's HyperCard is one
of our inspirations; simple, yet
powerful.
PythonCard uses wxPython. If you are
already familiar with wxPython, just
think of PythonCard as a simpler way
of doing wxPython programs with a
whole lot of samples and tools already
in place for you to copy and subclass
and tools to help you build
cross-platform applications.