fastest way to ghost/image multiple machines?

[Steve Franks]

I'm interested in how to specify a release and a bunch of packages,
and squirt it to multiple machines.  Or perhaps I'd like to spec the
current binary contents of my machine (sans config files) so I could
rebuild it from scratch later, without backups, or perhaps install
another machine with my current set of packages, but 7.x instead of
6.2, etc.  Permutations on this theme seem endless, and don't appear
to be focused on in the handbook.

Also interested in installing to a spare disk in my system, then
putting said disk in another system.  I always get errors after
label'ing when I try it, presumably because I already have a
filesystem mounted as root, and it trys to mount the new one as root
to copy onto...

Steve