There probably won't be a modification for it but check google or some tutorial websites for tutorials on how to do it for banners then just apply the same technique to the signature images. (Most involve a separate PHP script which is use as the image location, instead of a real image)
Thank you very much for the reply. I've found a script that works, but only for me. I've had to create a php file in a new folder in my site's public html. But to create a new folder for each member,.. Not practical, lol. There has got to be a way to incorporate this into vBulletin.
Thanks, but that's more of a video for an avatar. What I'm wanting is something in a sig or profile that only changes once the page is refreshed, or they view a different post in a different thread.