To include it with default lowpost.net colors, add the following code to your HTML template:

<script src="http://lowpost.net/widget/lowpost_news.js"></script>

If you'd rather apply your own style, define the classes .lowpost_widget, .lowpost_title, .lowpost_title_link, .lowpost_item, and .lowpost_item_link in your CSS file, and then add the following code:

<script src="http://lowpost.net/widget/lowpost_news_nostyle.js"></script>

Code for striketwo.net and faircatch.net is also available:

<script src="http://striketwo.net/widget/striketwo_news.js"></script>
<script src="http://striketwo.net/widget/striketwo_news_nostyle.js"></script>
<script src="http://faircatch.net/widget/faircatch_news.js"></script>
<script src="http://faircatch.net/widget/faircatch_news_nostyle.js"></script>

UPDATE: For sites like WordPress.com that don't grant HTML template access, you can instead use a generic RSS sidebar widget with one of the lowpost.net RSS feeds (like http://lowpost.net/feed/rss2.0/) for a similar effect.

As always, contact me if you have any feedback.