[Zope] Registering people in CMF as "Guests"

[BZ]

I have a couple of CMF sites and really love it (reeeeeeeeally I do), but
I have a new project where I need to have people be able to register as a
"Guest" (different role) or as a "Member" (the role register does now). I
poked around some of the scripts but I cannot seem to find anything that
shows me what role they get out of the box or where to change that.

Anyone done this?

Probably something darn simple I am missing.

Thanks,
BZ