node
A project I'm working on required a user's signature be displayed on the user's blog posts (only on the page—not in blog teaser listings), and after much wrangling, I figured out how to put the 'Biography' (one of the user profile fields) into the nodes when they were viewed individually.
Here's the snippet (to be placed into node.tpl.php or node-blog.tpl.php):
<?php if (!$teaser): ?>
<?php $account = user_load(array('uid' => $node->uid)); if (!empty($account->profile_bio)) { ?>
<div class="blogger-bio"><?php print check_plain($account->profile_bio); ?></div>
<?php } ?>
<?php endif; ?>The code basically checks if the user's account has a bio filled out, and if so, it will place it at the end of the node if the node is viewed by itself (if it's not showing the teaser).
See comments below this post for some important security considerations and alternate options.