[plug] debian/ubuntu package list copy for new install

[Michael Holland]

Folks,
I'd like to install on a new box all of the packages that are installed on
an existing PC.
  What is the appropriate way to do this? I guess just generate a text
list of installed packages, and "apt-get install `cat my-list` "?

It is proving difficult enough just to find a neat way to list all
installed packages.  The APT Howto is a useful starter, but what is a
good reference to the debian package system?