Normally APT requires direct access to a Debian archive, either from a local
media or through a network. Another common complaint is that a Debian machine
is on a slow link, such as a modem and another machine has a very fast
connection but they are physically distant.
The solution to this is to use large removable media such as a Zip disc or a
SuperDisk disc. These discs are not large enough to store the entire Debian
archive but can easily fit a subset large enough for most users. The idea is
to use APT to generate a list of packages that are required and then fetch them
onto the disc using another machine with good connectivity. It is even
possible to use another Debian machine with APT or to use a completely
different OS and a download tool like wget.
This is achieved by creatively manipulating the APT configuration file. The
essential premis to tell APT to look on a disc for it's archive files. Note
that the disc should be formated with a filesystem that can handle long file
names such as ext2, fat32 or vfat.