non-package software additions, and other modifications

[cross at revivesystems.com (Chris Ross)]

   I'm using a fairly long and complicated make-live command-line at  
the moment.  I'm including a bunch of other standard distribution  
packages, making a stable/etch liveCD, and changing the username and  
hostname.  This is all working fine.  The things I haven't found an  
obvious way to do yet are:

   1) Add the "user" (the one specified with the kernel argument  
username=) to the "disk" group.
		I don't know where this "adding the user to various groups" thing  
is done.  During [livecd] system boot?  Can/should I modify that  
behaviour, or just have a hook that pre-adds the user to the group in  
the group file?  (I did that first...)

    2) Install files (a local application, but really this would  
apply to any files) from the local system I'm building on, rather  
than via an aptitude get from the standard debian distribution(s)

   I suspect I just need to dig down a little lower in live-helper,  
and that these things can be done by using the underlying components  
rather than *just* using make-live.  But, while doing that, I thought  
I'd ask for pointers.

   Much thanks!

                                                - Chris