All technologies can be defined as extensions of different parts of our body.
When a radio listener can hear a song his favorite DJ is playing 30 miles away,
his ear is being extended by radio technology. When you are gossiping with a
friend over the phone who is thousands of miles away, your mouth and ears are
being extended by telephone technology. When you are watching your favorite
show on television, your eyes and ears are being extended by television
technology. When you take a trip in your car, your car is in effect an extension
of your legs. Tools extend our muscles, as anyone who has ever tried to pull
a nail out of a piece of wood can attest to. The computer is an extension of
the mind since a computer can't do anything that a man or woman with pencil
and paper couldn't do. It might take the man or woman several hundred years
to do something that a computer could do in a fraction of a second, but they
could still do it. What computers do is very simple, it's just that they do it
so incredibly fast that it seems amazing. Technology is nothing new, it has
been with us since the first primitive man first picked up a bone or a tree limb
and smashed his prey over the head with it. The first body part extension,
and mankind was on its way to world domination.

Peter Honan