Not a hack, but a request...
 

How do I get it so that i can use $username or something like it, so that I can use it around my boards? Like, say you want someone to read a thread -- it draws their attention beacuse *they think* that it's addressed to them, but it's really whoever's looking at it....sorry for the inconvenience, again...

You can use the variable $bbuserinfo[username] anywhere in your templates to show the user's username on the page.

For that to show up in a post, that requires a hack, written by Firefly - search his profile.