I watch a lot of learning material at 1.5x speed or even 2.x speed. When a presenter talks slow or you feel the material just isn’t moving along fast enough, you can save a lot of time by accelerating video playback. Here are a few ways that I do it.
YouTube
It is possible to watch YouTube videos at increased speeds directly in your browser, but you have to enable YouTube HTML5 to do so.
Visit the HTML5 trial page and click the button to join the trial. You may or may not need to restart your browser to see the slightly altered version of the YouTube video player, with playback speed controls at the bottom right. (Currently under the gear icon where Quality settings have been.)
VLC
My preferred method of viewing videos at an increased playback speed is by using VLC media player. I prefer VLC because the audio quality is superior during accelerated playback and there are shortcut keys such as instant rewind. VLC is available for free from VideoLAN. Learn the shortcuts for instant rewinds and accelerations; My favorites are Ctrl+Left, Shift+Left, Alt+Left, and the [ ] bracket keys.
Ripping YouTube Videos
In some cases I decide I would like to have a copy of the YouTube video for watching in VLC instead. I do this because I can watch videos in bulk, without internet, and do so with superior sound quality offered by VLC during increased playback speed.
To rip YouTube videos I use Firefox equipped with the add-on “Flash and Video Download”. (Sorry, couldn’t find a good ripper for Chrome.) Simply view the video in FireFox and use the custom menu at the very top right of the browser. This works for ripping plain old flash videos as well. If you are downloading a lot of videos, you might consider “DownThemAll!” for Firefox as well which works pretty well as a download manager (optional), and if you do, you will instead want to use “Easy YouTube Video Downloader” which works only with YouTube, but will correctly name the files when downloaded through “DownThemAll!”. Once the video is on your PC you can watch with VLC for the best experience.