That's not hard to do at all and won't affect the queries one way or another. Just open up your myvbindex.php file and look for:
PHP Code:
$threads=$DB_site->query("SELECT thread.threadid,thread.title,thread.replycount,thread.postusername
You would just replace "thread.postusername" at the end of that with "thread.lastposter". Then you would want to edit your index_threadbit template and replace this:
by <a href="$bburl/member.php?s=$session[sessionhash]&action=getinfo&userid=$thread[postuserid]">$thread[postusername]</a>
with this:
by <a href="$bburl/member.php?action=getinfo&find=lastposter&threadid =$thread[threadid]">$thread[lastposter]</a>