How do I post a youtube video?

To post a youtube video you need to find the url of the video to post.  When viewing a video on youtube, there are two text boxes near the video information:  one titled URL,  one titled Embed.  Both contain the same url, but the URL variant is easiest to work with.  The url will be in one of these formats:

http://www.youtube.com/watch?v=Sog9cgX-39Q

http://www.youtube.com/v/Sog9cgX-39Q

The portion highlighted in bold is the movie id.  To embed a youtube video here, simply wrap the id in youtube tabs like this:

[youtube]Sog9cgX-39Q[/youtube]