I generally like to watch lot of conference videos and lectures in youtube. Most of the time these videos are long (> 1 hour) and sometimes the speakers speak slowly. I wanted to see if there is a way by which I can increase the playback speed of the videos.
Luckily I stumbled upon the HTML5 experiment page of Youtube, which allow you to control the playback speed.
So, if you are interested in controlling the playback speed of youtube videos, then just go to youtube html5 experiment page and enable it. You should also be using one of the latest browsers for this feature to work. I think youtube is saving this setting per browser and not per user account.