<div id="socialntwrk">
<?php if(get_the_author_meta('twitter', $curauth->ID) || get_the_author_meta('facebook', $curauth->ID) || get_the_author_meta('linkedin', $curauth->ID) || get_the_author_meta('digg', $curauth->ID) || get_the_author_meta('flickr', $curauth->ID)): ?>
	<ul>
			<?php if(get_the_author_meta('twitter', $curauth->ID)): ?>
			<li><a href='http://twitter.com/<?php the_author_meta('twitter', $curauth->ID); ?>'><img title="Follow me" src="http://sharecommons.com/images/twitter.png" alt="Twitter" /></a></li>
			<?php endif; ?>
			<?php if(get_the_author_meta('facebook', $curauth->ID)): ?>
			<li><a href='http://www.facebook.com/<?php the_author_meta('facebook', $curauth->ID); ?>'><img title="Become a fan" src="http://sharecommons.com/images/facebook.png" alt="Facebook" /></a></li>
			<?php endif; ?>
			<?php if(get_the_author_meta('linkedin', $curauth->ID)): ?>
			<li><a href='http://www.linkedin.com/in/<?php the_author_meta('linkedin', $curauth->ID); ?>'><img title="Connect with me" src="http://sharecommons.com/images/linkedin.png" alt="Linkedin" /></a></li>
			<?php endif; ?>
			<?php if(get_the_author_meta('digg', $curauth->ID)): ?>
			<li><a href='http://digg.com/users/<?php the_author_meta('digg', $curauth->ID); ?>'><img title="Digg me" src="http://sharecommons.com/images/digg.png" alt="Digg" /></a></li>
			<?php endif; ?>
			<?php if(get_the_author_meta('flickr', $curauth->ID)): ?>
			<li><a href='http://www.flickr.com/photos/<?php the_author_meta('flickr', $curauth->ID); ?>/'><img title="My Flickr" src="http://sharecommons.com/images/flickr.png" alt="Flickr" /></a></li>
			<?php endif; ?>
	</ul>
<?php endif; ?>

<?php endforeach; endif; ?>
</div>

http://wordpress.org/support/topic/templating-authorphp

Wordpress author pages with custom fields in profile

PHP