[Mark.B]

Unduly complex.....there *is* a way to do it easily with a plugin.

*This code is NOT my own, it is posted elsewhere on vbulletin.org, but I have not managed to find it again.

Create a new plugin as follows:

Product: vBulletin
Hook Location: global_complete
Title: Whatever you want to call it

$output = str_replace('[username]', $vbulletin->userinfo['username'], $output);

Now you simply start a thread with [username] in the title and everyone who views it will see their own username there.