All of these can be accessed via the popup legend using the full reply feature or by typing the following code:
[GT]video id number[/GT]
[moddb]video id number[/moddb]
[livestream]Channel Name[/livestream]
We have taken a look at several other sites that provide similar video capability, but not all are compatible enough to be placed on the forums, but we hope that these will come in useful. Sadly Gametrailers don't allow for HD embedding.
And just to prove it, here are some examples