YouTube now allows you to add timestamps in the embedded video clips. Assume that you have a very long video and you want users to start viewing the video from a particular time onwards, then you can use this method. Let me illustrate this with an example:

Here is the html code for embedding a video from Youtube. It is the official trailer of the movie Following (one of my favourites) :

<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/5q8bBAKNSA8&hl=en_US&fs=1&rel=0">

</param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always">

</param><embed src="http://www.youtube.com/v/5q8bBAKNSA8&hl=en_US&fs=1&rel=0" type="application/x-shockwave-flash" allowscriptaccess="always" 

allowfullscreen="true" width="425" height="344"></embed></object>

And if you play the video clip, it will start streaming from the beginning.

And if you watch this trailer you can see that it also carries some reviews. If I want people to watch the clip from the portion where the review appears (around 60s in the time scale) , then I need to put that as a ‘start’ parameter in the embedded html code as shown below:

<object width="640" height="385"><param name="movie" value="http://www.youtube.com/v/5q8bBAKNSA8&hl=en_US&start=60">

</param><param name="allowscriptaccess" value="always"></param><embed src=http://www.youtube.com/v/5q8bBAKNSA8&hl=en_US&start=60 

type="application/x-shockwave-flash" allowscriptaccess="always" width="640" height="385"></embed></object>

Just click on the embedded video file given above to see the difference!

Similarly, you can also create URLs in this way. All you have to do is to add the parameter ‘t’ at the end of the YouTube URL as shown below.

http://www.youtube.com/watch?v=5q8bBAKNSA8#t=60s

Have fun!