Changes I made:
example: http://overnights.org/profile/2
style.css
#userinfo { margin: 10px 0 5px; width:45%; float:left;}
#userinfo dt { font-weight: bold; }
#userinfo dd { margin: 0 0 5px; }
#useractivity { margin: 10px 0 5px; width:45%; float:right;}
#useractivity dt { font-weight: bold; }
#useractivity dd { margin: 0 0 5px; }
profile.php
<?php bb_profile_data(); ?>
<div id="useractivity">
<h3><?php _e('User Activity') ?></h3>
<dt><?php _e('Recent Replies'); ?></dt>
<?php if ( $posts ) : ?>
<?php foreach ($posts as $bb_post) : $topic = get_topic( $bb_post->topic_id ) ?>
<dd><a href="<?php topic_link(); ?>"><?php topic_title(); ?></a> <?php if ( $user->ID == $bb_current_user->ID ) _e('You last replied'); else _e('User last replied'); ?>: <?php bb_post_time(); ?> ago.
<?php
if ( strtotime(bb_get_post_time()) < strtotime(get_topic_time()) ) {
echo ' <span class="freshness">'. __('Most recent reply: ');
topic_time();
echo ' ago.</span>';
} else {
echo ' <span class="freshness">'. __('No replies since.') .'</span>';
}
?>
</dd>
<?php endforeach; ?>
<?php else : if ( $page ) : ?>
<?php _e('No more replies.') ?>
<?php else : ?>
<?php _e('No replies yet.') ?>
<?php endif; endif; ?>
<dt><?php _e('Threads Started') ?></dt>
<?php if ( $threads ) : ?>
<?php foreach ($threads as $topic) : ?>
<dd><a href="<?php topic_link(); ?>"><?php topic_title();
?></a> <?php printf(__('Started %s ago'), get_topic_start_time()) ?>
<?php
if ( strtotime(get_topic_start_time()) < strtotime(get_topic_time()) ) {
echo '<span class="freshness"> '. __('Most recent reply: ');
topic_time();
echo ' ago.</span>';
} else {
echo '<span class="freshness"> '. __('No replies.') .'</span>';
}
?>
</dd>
<?php endforeach; ?>
</div>