I know Hobbit said he was working on the next VB version, so I figured I'd throw this out there as an idea to add.
http://www.vbulletin.org/forum/showthread.php?t=242733
Basically it allows you to "tag" users like twitter does. If I wanted to "tag" Hobbit in a post, I would do @Hobbit; and it would appear like Hobbit so.
The tagged user gets a notification they were tagged in a post and allows them to see which one. The car forum I'm apart of does this and it's VERY, VERY useful in discussions.