I like the Aptana PHP formatter. Its the only one that works well for me. I used to my one liner tags messed up a lot like this.

<?php echo $content
?>

What I noticed was that the ones with the semi-colons in place didn’t break to a new line.

<?php echo $content;?>

Now the auto-formatter (Keyboard shortcut to Command + Shift + F on the Mac) keeps things in the same line.