I just learned that you can force a Youtube video to start from a specific point in time. You do this by adding a time tag to the video link. It is quite useful when you want to send the link to the friend but have the video skip the boring part. Here is how it works.
1. Take the link of the video you want to watch or send someone, for example http://www.youtube.com/watch?v=LjhCEhWiKXk
2. Add a time tag to the end of the link, for example #t=0m39s.
3. The link will be as follows: http://www.youtube.com/watch?v=LjhCEhWiKXk#t=0m39s
You are ready. When you click the link, the video will start playing from the 39th second into the video.