How to put windows into groups by application type.

Hi,

I would like ratpoison to automatically create groups for each
application type I am running (e.g. one group for all urxvt windows,
one group for all uzbl windows, etc.) and place all windows of that
application into the appropriate group.

I have written a small script that achieves this goal when I start the
application through it. This works ok for applications that have only
one window and I explicitly start on the command line, but not for
applications that open additional windows while running.

So, is there anyway that I could have ratpoison detect when a new
window was created and place it in an appropriate group?

Thanks,
Eric