If you have a 3D TV, simply connect your 3D-enabled TV to your PC as a second display using a HDMI or VGA/DVI cable.
Use the web browser of your choice to stream side-by-side formatted videos on your TV. You can even pre-download the scene and play it back using a regular media player like Windows Media Player or apple QuickTime.
On your TV, make sure it is configured for 3D viewing, otherwise, you will see the video in side-by-side format. To do so, go the the TV's menu, then select "Display" and then "3D". Select "Side-by-Side" format. Exit and turn on your 3D glasses. This may vary depending on TV manufacturers.

If your 3D TV has a USB port (most have), download the side-by-side video file to your PC, and then transfer it to your USB key. Remove the USB key from your PC and plug it in your 3D TV. From the TV menu, select the USB key has input, and select the video file. Make sure the 3D TV is in 3D mode. To do so, go the the TV's menu, then select "Display" and then "3D". Select "Side-by-Side" format. Exit and turn on your 3D glasses. This may vary depending on TV manufacturers.

Desktops and Laptops equipped with a 3D monitor can readily play the movie in 3D mode. Follow the manufacturer's instruction to do so. Below is a list of known 3D laptops and desktop monitors:

If you don't have a 3D TV or 3D laptop/desktop, you can still view 3DpornVids.com content in 3D. Simply download/stream the "Anaglyph" format video from 3DPornVids.com. Using regular "Red/Cyan" 3D glasses, you can watch our movies in 3D.
