Search Engine Roundabout was doing some digging around on the YouTube help forums, when it found a thread discussing a "3D feature".
Further snooping found staff member "YouTube Pete", a "developer working on the stereoscopic player as a 20% project" (the one day a week Google engineers get to work on projects outside their job descriptions), answering questions on the little-known feature.
Pete offered up the tags for film makers to upload their own 3D video content in various formats, and also helped with some troubleshooting as well.
It's interesting that the roll out of this seems to have been so muted, but by Pete's own admission it is still in its "very early" stages and running with lots of "silly bugs".
For more deets, head over to the original YouTube post and let us know what you think to the new project below.