gdm+ssh-agent

[Julian King <jpk28 cus cam ac uk>]

Hello,

I've trawled teh GDM reference manual (on http://www.socsci.auc.dk/~mkp/gdm/)
and there doesn't seem to be any other things like a FAQ, so I'll post
here.  If someone knows of other documentation then I'd be interested
to see that too, as well as a direct answer to the question.
The question is how can I use gdm and ssh-agent?  Under xdm I
can use .xsession to launch the window manager, so I can arrange via 
some cunning execs to make everything a child of ssh-agent.  As far
as I can see this doesn't work with PreSession files.

Any thoughts/ideas/hints?

Julian