Make a virtual printer?

[Tom Horsley]

I'd like to make a "printer" on my fedora box that actually just
generates a series of .png files for each page in a print image
directory.

I've found all the info I need to pass to ghostscript to get it
to do this (it has a handy png output driver built in), but
brain matter starts leaking out my ears when I try to understand
how to invent a .ppd file and integrate this with cups so I can
spool things to this "printer".

Anyone out there ever done such a thing and have some cofig files
I could steal?