I thought this could do with being stickied or something because there are a lot of posts where they can't post the video properly because of the new format
How its done is if you take the bit after the = so its just letters, in the case of this clip
http://www.youtube.com/watch?v=cG07DqewQN0 it would just be cG07DqewQN0. Its THAT code that goes into the tags, not the whole URL, so it would be
[yt]cG07DqewQN0[/yt ] (without the space)