The tech is very simple, really, and has been around in more primitive mechanical form for, oh, a century at least. Each eye sees its own perspective into the world, and the parallax difference is integrated by the brain to give us a 3D view, or stereoscopic vision. All that needs to be done is have 2 images captured from the appropriate perspectives, and supply each eye with the corresponding image exclusively.
There are different methods for achieving this with film, with the most recent one I know of being 2 overlapping projections with the light somehow polarized differently. Eyeglasses filter out the opposite polarity and you get a mostly exclusive view of the correct perspective in each eye.
For TV, the old red/blue method I think sucks. But what they're pushing now is a refresh rate that is double the frame rate, then having LCD glasses that ping-pong shutters so that each eye only sees the appropriate perspective. (In practice, the frame rate would be 120 Hz, where each consecutive pair of images is 2 perspectives into the same scene and moment, and each of the images is fed only to the correct eye, giving you stereoscopic vision at 60 Hz.) I have yet to experience this for myself, but I see no reason why it shouldn't work properly. My only question is how bulky (and dorky) is the eyewear to make this possible?
