How to Share YouTube Videos on Your iPhone
Not only can you view YouTube videos on your iPhone, you can share them with your friends by using the iPhone's e-mail application. Share any YouTube video as you are watching it by tapping the e-mail button. When you do so, one of the iPhone’s virtual keyboards pops up. The iPhone has already filled in the e-mail subject line with the name of the video. And the body of the message is populated with a link to the video on YouTube. All you need to do is fill in the To field with the e-mail address of the person you are sending the link to along with any additional comments.
Alternatively, from the list of videos, tap the blue button with the right-pointing arrow to see all sorts of details on a particular video. You’ll see a description of the video, the number of people who viewed it, the date it was added, and other information. From there, tap the Share button to bring up the iPhone’s e-mail program.