Notice: youtu.be links will not work for embedding.
Updated YouTube video embedding instructions:
1. Select the "Share" tab
2. Select the "Embed" tab
3. Select "Use old embed code" checkbox
4. Copy the link and paste the address part between the [tube ][/tube ] tags in your post.
For example, in the above embed code, you would use this part:
[tube ]http://www.youtube.com/v/e7pyQsFAqF8?[/tube ]
You can also just go to the URL of your YouTube video and copy all of it before the ampersand (excluding the ampersand). In *most* cases this will work (assuming the URL is www.youtube.com).