I have some 3-D videos taken by my HTC EVO 3D camera on my YouTube channel. When you open one of the 3-D videos, at first you may see two side-by-side frames something like this:
To view these when you don't have a 3-D device, hit the pause button. Then, find the 3D menu on the bottom right. It looks like this:
Choose the "No glasses"Select the “No Glasses” option: