Matt,
Excellent, thanks for your sharing. As I mentioned, our module also support more easy way to do it from v3.7.1. Just follow the steps below:
1) Enter the "Customize" panel from dashborad.
2) Switch the "widget" tab and choose the "Footer in the post" item from the dropdown list.
3) Cope the code like that:
<iframe src="http://www.facebook.com/plugins/like.php?href=[permalink]&layout=standard&show_faces=true&width=450&action=like&colorscheme=light" scrolling="no" frameborder="0" allowTransparency="true" style="border:none; overflow:hidden; width:450px; height:70px;text-align:left;"></iframe>
4) Click "update"
It will work well and please visit here to see how it action - The Latest in Blogging Innovation
Later we will convert it into a tutorial with more detail, including Matt's way. Hope it makes sense.
Kind Regards
Baldwin