YouTube Annotations – How to Permanently Disable Video Annotations

To change the setting fort this, follow the steps below:

1. Go to your Settings page.
2. Click the Playback Settings link.
3. Choose between the default setting and the “I have a slow connection” setting.
4. Click the Save Settings button.

I believe this feature was removed in 2011.

Though it does still seem to show up on their docs:http://support.google.com/youtube/bin/answer.py?hl=en&answer=2481140

You may have to use the Content Manager: https://cms.youtube.com