Ok, I've got it figured out. Instead of the way you had it above...change it to this:
Code:
Posted By <a href="<?php the_author_url(); ?>"><?php the_author() ?></a> @ <?php the_time('F j, Y @ g:i a'); ?>
Change it in both the single.php file and index.php file. It will thus link the author's name to whatever URL they fill in on their wordpress profile.
I tested it on my site and it works. Glad you had this question cuz I was wondering myself, but had been too lazy up til this point to actually investigate or even attempt to figure it out.
