Sample video with 3D options:http://www.youtube.com/watch?v=ihvhIPHiDNg
HOW TO MAKE 3D YOUTUBE VIDEOS - Yuriythebest's Don't Ask Me Again Guide
1. Make a 3d video in cross-eye (right/left) format using a 3D webcam or watch Wheatstoneholmes tutorial
on how to just use two regular webcams for this. Alternatively, you can use a dual miniDV camera rig, paired digital cameras, or an upcoming S-3D camera.
2. Upload your video to YouTube.
3. Write "yt3d:enable=true" as the last tag in the "TAGS" field.
Thanks to YouTube user Escalus84 who informed me of this. He has many great 3D videos, so check out his channel!
NOTE: If you already uploaded the video in parallel, you can make it work correctly by adding the "yt3d:swap=true" as the last tag.
Now, for this feature to be l33t they should add interlaced and iz3d outputs.
MTBS EDIT: iZ3D 1.10RC1 drivers are compatible with side by side output when switched to full screen mode. This is a Vista ONLY feature.