If you were the only child in the Western World who did not have a
Viewmaster (ViewMaster TM registered ) and some round-slides for it
then you dont know what the Viewmaster experience is. Have a look at
the original Viewmaster toy and more recent versions at the web site
http://www.3dstereo.com/. (It's not my website nor am I affiliated in
any way with it.) While it may not have been recent, you have seen 3D
pictures through this thing, no doubt.

No it is not the same as the green and red plastic glasses at 3D
movies, or 3D comic-books. Yes there are cameras commercially
available which take quality 3D pictures.

Yes if you place two cell-phone cameras side by side (about the
separation of your own eyes) and place the viewing screen of each
phone such that each screen is visible only to one eye, then you will
"see" a fully stereo cell-phone camera based picture.

Note that the 3D picture experience is in your head , not in the
cameras, or your eyes. and yet, the scene that you experience in 3D
'feels'-like* it is 'out there' beyond the location of your eyes.
Just like the experience of yellow 'in' the 'bar-chart' (illustration)
and its 'bars' 'feels'-like the yellow 'occurs' ('exists') at/on the
'bar', which is 'on' the screen.

Just as you 'see' the yellow of the bar, you 'see' the bar / rectangle
itself, whether as a yellow solid or some rectangular outline with a
yellow interior. There is no yellow there. It is only a place where
certain electromagnetic radiation comes from and your eyes are able to
detect that radiation and your nervous system / brain does something
with the signals comprising that detection.** Now consider that since
there is no yellow there there is also no bar or rectangle there
either, just electromagnetic radiation. Here we get close to the
notions implicit in "I've seen a cat without a grin, but never a grin
without a cat." (about The Chesire Cat, from Alice in Wonderland).

Some robotics systems have twin "steerable" cameras, such as COG
http://www.ai.mit.edu/projects/humanoid-robotics-group/cog/ , NASA's
Robonauthttp://robonaut.jsc.nasa.gov/ ,
Kismethttp://www.ai.mit.edu/projects/humanoid-robotics-group/kismet/kismet.html
.
Cog, for example, has stereo vision capability because the two cameras
are 'locked-together' and 'point at the same place' . BUT, the
'vision' is not for humans to see through a stereoscopic viewer but
rather by a bunch of computerized algorithms which analyze the heck
out of two TV raster-matrices, basically a bunch of numbers in a
sequence with an associated 2D index into them. As a result of
"artful" processing (and algorithm design) the computer-robot system
is able to 'visually detect' objects and orient the camera 'eyes' of
COG towards objects and people and track movement. One could endlessly
speculate on a comparison between what COG's processing accomplishes
vs "seeing" in a human. Perhaps a perusal of those algorithms might
help. (I don't have a copy of those algorithms or I'd show them to
you. On the other hand you are now spared having them shown here at
length.)
I chose 'visually detect' carefuly, because I don't think that
'perceive' (anything like a human does) is accurate to describe COG's
' 'vision' ' . COG is able to operate a Slinky toy (TM) with 'his'
'hands'. Publicly available video of this has been shown. I doubt that
any 'understanding' of this which COG 'has' has much depth to it. This
is where (presently) even intelligent machines differ from humans (of
most any age).

*'feels'-like. Another example of 'feels'-like, which everyone can
relate to, is the following. When you walk along a semi-crowded
sidewalk you walk so as to not collide with other occupants. You do
not have GPS, nor a laser-rangefinder, you do not know with any great
precision where anybody is located, including yourself, nor do you
know precisely the path each will take and in what manner. You do have
a sense of a three-dimensional space around yourself, and a sense or
*'feeling'* of the morphology / volume / mass of the walkers, and a
'feeling' of (relative to you) where the occupants are and their short
term travel (path and general manner). That 'feeling' is not at all a
visual-theatre created by and in your mind's eye. It is wholly a
non-linguistic and non-visual mental occurrence which you are aware of
but usually carelessly pay almost no attention to. You proceed to
('automatically') walk (with no deliberation about it) to go in the
desired direction and without colliding with the other people or
things in the environment, like mail-boxes and fire-hydrants.

Such 'feeling' (or sense) is what the "attention system" of the human
mind (limbic and other) produces as output for consumption by one's
'awareness' or consciousness. The source of this 'feeling' (sense) is
the output of processing performed in the subconscious. (1)
Not Freud's (circus of the) subconscious. Perhaps a different term,
'pre-conscious'. The content of such awareness is (in the case being
discussed) un-crisp, unlike most material handed to the consciousness
from the subconscious. In a sense the consciousness is too finicky
about the packaging of its input and so some input such as the one we
are discussing results in vague, uncrisp awareness contents. It is
these 'feeling' items, however, that the 'nobody home' subconscious
can process to deal with the world that each of us finds ourselves in.
Air traffic control / collision avoidance processing (with no
accompanying consciousness) can take place expediently in the
subconscious. No (or rather little) time-expensive (frontal-cortex
type) serial deliberation takes place in the 'server room of the
subconscious'.

I will provide further discussion of 'feels'-like at a later time. It
is one of the important aspects of neural / mind systems which Antonio
Damasio, in his book "The Feeling of What Happens", explains.

(1) metaphorically, think of the subconscious as a building that is a
server room filled with thousands of blade servers and in the totality
of all those petaflops 'nobody is home'. Metaphorically, visual
displays, printers and such provide a transition from the bazillion
bits and algorithms of the server room to input to a human. The human
here represents conscious awareness.

**For persons with synesthesia,
http://en.wikipedia.org/wiki/Synesthesia, letters or numbers are
perceived as inherently coloured, sometimes colours 'have sound'.
This kind of thing happens to perfectly sane, drug-free persons when
two sensory systems have a kind of cross-feed. Signals coming from the
eyes activate parts of the auditory system as well as the visual
system. We all know of cross-sensory metaphors (e.g., "loud shirt",
"bitter wind" or "prickly laugh"), these occur in linguistic
communities because this cross-circuiting of sensory information is
not wholly uncommon in the human population.