Creating a backup of the system

[João Silva <joao@innerghost.net>]

Hi all,

how can I create a backup of the system? What I mean is, I have lots of
packages installed; is there a way to save the list of packages that are
installed, and then use that list in another computer to create a system
similar to mine?

I know there is /var/lib/dpkg/status; is there a way to install all the
packages listed there in a freshly new installed debian system (already
configured to use apt-get)?

Also, /var/cache/apt/archives is using a lot of disk space; can I
delete all the files? Or is there any way to clear this cache?

Thanks for your time,

João