Google is pushing out a new 3D feature for users that upload high definition video. This 3D conversion process was originally added as a beta test during September 2011. A 3D camera was recommended for better results however the process works for all 2D video uploaded in high definition quality regardless of camera.
Currently majority of the 1080p videos less than 15 minutes of length are being converted automatically. Google is using its massive cloud computing infrastructure to convert these videos. In order to switch over to the 3D view, users must click the gear icon in the toolbar of the video. If the video has been converted over to 3D already, an icon will appear to the left of the gear icon and switch the video to the 3D view when clicked. The user can click the 3D icon a second time to bring up a variety of viewing options.
Users with colored glasses can choose from “Red / Cyan, Green / Magenta and Blue / Yellow” depending on the shade of the glasses. A user can watch the video in “Optimized” view to remove pure red and pure cyan. While the colors are less vibrant in most videos, this view reduces the amount of ghosting in the video. Follow the source link to try it out yourself.
Source: Official YouTube Blog