I should have mentioned that anything that uses apt for installation, like apt-get or aptitude or synaptic or even the "software centre" downloads the debs into /var/cache/apt/archives. So all you need do to keep a copy of a package deb is to make a dir to hold your stuff e.g.
Easy as that. The point about only having files in /usr that came from a .deb cannot be stressed enough. If you manually copy stuff in, it will break something sooner or later. It is an absolute CERTAINTY.
I should have mentioned that anything that uses apt for installation, like apt-get or aptitude or synaptic or even the "software centre" downloads the debs into /var/cache/ apt/archives. So all you need do to keep a copy of a package deb is to make a dir to hold your stuff e.g.
sudo mkdir -p /usr/local/backup
and then copy the file(s) in e.g.
sudo cp /var/cache/ apt/archives/ adobe-flash* 11.1.102. 63*.deb /usr/local/backup
to install one or more .deb or you do e.g.
sudo dpkg -i /usr/local/ backup/ adobe-flash* 11.1.102. 63*.deb
Easy as that. The point about only having files in /usr that came from a .deb cannot be stressed enough. If you manually copy stuff in, it will break something sooner or later. It is an absolute CERTAINTY.