gistfile1.php

<!-- Inside the loop, for each post -->
<a href="http://twitter.com/share?url=<?php print(urlencode(get_permalink())) ?>&amp;text=<?php print(urlencode(get_the_title())) ?>" class="twitter-share-button" data-count="horizontal" data-via="thomasfuchs">Tweet</a>

<!-- in your footer -->
<script type="text/javascript" src="http://platform.twitter.com/widgets.js"></script>