Fully transparent windows in Pygame?

Is it possible to get a fully transparent window in Pygame (see the desktop through it)? I've found how to create a window without a frame, but there doesn't seem to be any obvious way to make it transparent.

I'd be willing to tie into system-specific technology/frameworks as long as there are solutions for both Windows and Mac OS X, but I'm not sure which direction to be looking.

The only topic I was able to find recommended using wxPython, which isn't something I can do for this particular project (needs to be Pygame).

From stackoverflow

• PyGame uses SDL, which does not support transparent windows. Although at least on Linux making it transparent is done by the window manager, not the application.

  Alec Thomas : True, generally the WM does provide transparency effects, but applications can also explicitly enable transparency. urxvt is an example of such an application.

  One Crayon : Sucks that the answer is "no". Darned limitations of external libraries!