It was not possible untill recently to start the video at a specified time. The user had to wait till the 6’th minute and 10’th second then watch the video. But now with a small tweak in the URL [eg.http://www.youtube.com/watch?v=ABCDEFG] you can change it to
http://www.youtube.com/watch?v=ABCDEFG#t=6m30s
and that will start the video at 6 min 30 sec. This is a very small tweak but very very useful.
Let’s examine closely what extra # we typed does
t= time, m=minutes, s=seconds. So if I type #t=6m30s it means 6th minute and 30’th second ; the video will start exactly at the time specified.