I've found a way of adding Youtube videos to the forum without having to enable html code in the forum which is a huge security risk.
I also added a youtube icon in the 'Post Message' editor for an easy way to add a video.
How to add a video:
When you find a vid on youtube that you wanna put on here copy the part of the vids web address after the = (equals sign).
An example of what you'll see in the browsers address bar when viewing video:
http://www.youtube.com/watch?v=NHC_Qyov2Xc
The bit you want to copy with your mouse:
NHC_Qyov2Xc
Paste the code into the forums editor and hightlight it with the mouse.
Click on the Youtube button to wrap the youtube tags around it.
Important: Make sure the code and youtube tags are all on the same line otherwise it won't work.
:thumbs