Use vBulletin as a comment tool?
 

I have a website with funny videos and pictures, and a forum to discuss funny stuffs.

I would like people to be able to comment on various funny pictures and videos.
Since I already have a forum for discussions, it would be like have 2 forums if I add a separate commenting application. So I was thinking integrating vBulletin to handle some very simply commenting would be a good idea.

Is there a mod, which would allow me to integrate the vBulletin into a commenting tool? If not, does anyone have any thoughts on how to accomplish this? Is this even a good idea to use vBulletin?

You can do it, but you would be best setting it up so that each time a new video/picture is create a new thread is created, then you can just to that page thread from your site. You could also make a textbox on your page might be a little more work but it would be good I think.

I doubt there is a mod made for this, you could try searching. If you don't get any hits then this thread shows you how to create posts (and also threads)