YouTube – How to Add a Video to ‘Watch Later’

I am not exactly sure but it depends on how the particular video is embedded from YouTube. You will see videos embedded in various different ways and dimensions.

Some videos are available for viewing at 240p while watched in YouTube but not when you watch the same video through some other site where it is embedded.

There is no such setting which makes the "Watch Later" button appear all the time. Also, as you are seeing the videos in a Google Reader Feed (or some other similar feeds/blogs), you are not even logged in to YouTube at all! Even if such a setting exists how can it be applied when you are not logged in at all?

P.S: Logging into one of the Google Service at a time does not means that you are logged into all the Google Services you use with the Account. Suppose you log into Google+ for four days and never open GMail during this period at all - in the GMail "Previous Login History" (at the end of your GMail Page") there will be no record of you logging in at all.

You cannot do this from the video player itself, but if you're watching the videos on a Youtube.com page you can add them to an existing playlist or new playlist using the "Add To" button under the video. You'll also have to be logged in to make this button work.