Horizontal preview box:
<script language="JavaScript" src="http://www.phdcomics.com/previewfeed_horiz.php"> </script>

<script language="JavaScript" src="http://www.phdcomics.com/previewfeed_horiz_2.php"> </script>

<script language="JavaScript" src="http://www.phdcomics.com/previewfeed_horiz_1.php"> </script>


Vertical Boxes:

<script language="JavaScript" src="http://www.phdcomics.com/XXXXX.php"> </script> ->replace XXXXX with:
previewfeed.php	previewfeed_2.php	previewfeed_1.php

The Mini Box:

<script language="JavaScript" src="http://www.phdcomics.com/previewfeed_mini.php"> </script>