If you don't hear from FireFly for a while .. :P
Code:
mail("$webmasteremail", "User $bbuserinfo[username] Unregistered", "Username ".unhtmlspecialchars($bbuserinfo['username'])." \n UserID $bbuserinfo[userid] \n Unregistered", "From: $webmasteremail\r\n");
eval("standarderror(\"<br><br>You've just been erased from our database, you are now browsing the forum as Guest.<br><br>\");");
should do the trick. I tried with username ^test*^'\er and that worked just fine.
Now.. all I need is an input field where users can give a quick reason why they no longer wish to be a registered member.