Thanks for the thumbs up!
Here's how you do what you're looking to do. By the way, this isn't directly related to my hack, but it does get the job done.
In index.php, around line 260, you'll see this line:
PHP Code:
$bbuserinfo['lastvisitdate'] = vbdate($dateformat, $bbuserinfo['lastvisit']);
Immediately after it, insert this line:
PHP Code:
$bbuserinfo['lastvisitdate'] .= " at " . vbdate($timeformat, $bbuserinfo['lastvisit']);
And you're set. I think you can probably figure out how to customize this. For example, if you want it to say, "You last visited Today, at 8:33 PM", you'd just insert a comma before the " at " in the above line.
That's it.