Private Messages light bulb

[SaintDog]

Chances are that would require some sort of hacking on the file part of vBulletin; at least if you are wanting it to appear on every page and use a graphic instead of a Java Pop-Up box.

Try asking over at vBulletin.org, the hackers there may be able to help you out a little more than over here since most of the edits here are strictly template editing; aside from a few basic alterations to the database.