What I want to do is to provide users with a booklet (such as Instapaper’s), which will send information (e.g., clicked time) about streaming video the users are watching when they click on it
For example, if I click on the point on 1m45s of a certain YouTube video, it sends the time to a server.
I don’t know much about YouTube and its API, but my guess is it would be difficult to do from watching a standard youtube player (at youtube.com for example), but might be possible on a customized youtube player using youtube player api?
I apologize that I jumped to asking before putting much effort into the APIs, but as I’m just evaluating possibilities rather than planning implementations, please regard this as more like a can-I question rather than a detailed how-to question.
The answer is yes. You will need to use the flash player and the Javascript API. The latter provides a means to get the current time of the video being played. You can also of course get listen for play event and then retrieve the current time and use an XHR request to send it to your server.
The best overview of all this is here.