Thank you mummatron for making it hyperlinkable!
(How'd you accomplish that?)
You're welcome my friend. On YouTube, click the 'Share' button under the video. The text box entitled 'Link to this video:' will contain the short link -
The short link won't embed as a video when posted on this forum. Also certain browsers won't render it an active link. So what you gotta do is click the little square box entitled 'Long link' to the right of 'Link to this video:' which'll give you http://youtube.com/watch?v=tRmZ9zH-mYM.
However, the long link as it is won't always embed the video. You will need to delete the 'www.' portion of the link first. If the hyperlink isn't active you can make it active by clicking the hyperlink icon (depicted as a linked chain) in the editing panel at the top of the forum posting box and pasting the link into the relevant box - just make sure the 'www.' is removed.