Here's a new vbCode to embed YouTube videos in your posts, rather than linking to the YouTube page.
Here's how it works:
To embed the video on this page:
http://www.youtube.com/watch?v=umbUCuCg264 copy the ID code
umbUCuCg264 (after http://www.youtube.com/watch?v=) and put it between the tags: [yt]umbUCuCg264[/yt]