Some links for 3-D HD videos have been showing-up recently, and they require a special player to view them. I found a freeware player that has good ratings (I've never used it myself), so if you want to check these titles out, you can download and give the player a shot.
NVIDIA 3D Vision Video Player 1.6.9 Or, get it from NVIDIA.
(Note: I have no idea if this player will work properly with any other gpu type - try it and see!)
For Linux, you can try the Bino Player - free and open source. There are instructions for compiling for windows and Mac, but be warned, it's not for beginners, and the project looks to be very much in the early development stages, so there isn't likely to be much individual support. The developer doesn't have time to maintain individual binaries himself, but you may find a recent one contributed by someone (a binary means a regular exe installation file for windows - and however they come for macs ). Currently there are binaries for both windows and mac (packaged in .zip files).
Vlc is also working on including 3-D support. It's still buggy, but you can take a look if you're interested.
Here's gspat's link to the Stereoscopic player
3-D Side by Side:
frame-sequential 3D when it comes to airing 3D content over cable to 3D TV.
As you may know that almost all 3D TVs display 3D content in frame-sequential format,
that doesn't mean that the input 3D signal has to be frame-sequential 3D. Since nearly
all 3D TVs can convert the 3D input in a variety of different formats on the fly to
frame-sequential format for display, this saves great effort for 3D viewers. Among the
different input formats, side-by-side 3D is definitely the most popular one.
How SBS 3D Works
In side-by-side 3D, a full 1080p or 720p frame is intended for both eyes at the same
time with two halves on the left and right, and the entire frame for the left eye and
right eye respectively scaled down horizontally to fit the left-half and right-half of the
frame. For example, for a 720p content (resolution of 1280 x 720), the frame for the
left eye will be 640 x 720 and the frame for the right eye will also be at a 640×720
resolution. When such SBS signal is received by 3D TV, the 3D TV will split each frame
to extract the frame for each eye, and then will rescale these individual frames to a full
HD resolution. Then these individual frames will then be displayed alternately in a
frame-sequential manner which is in sync with your active shutter 3D glasses.
But the best part...
SBS 3D files let you watch HD videos they way YOU want to, Using the Stereoscopic player Linked above.
On your 3DTV as full 3D (whatever format of 3DTV you use)
On Multi-Monitor Goggles
On 3D Computer Monitors
On Regular TV's and Computer Monitors as 3D Anaglyph
On Regular TV's and Computer Monitors as 2D
Don't have a 3DTV yet but plan to? Get these files and be ready, but still be able to watch them NOW!
(Thanks to gspat for this.)