Something that's been annoying me for a while is the lack of template tag definitions.
Today I gleamed the template code and found something that would help.
To identify between a listing page (a list of blog posts) and a detail page (a page dedicated to a particular post, where comments are shown), you need the following condition check.
<b:if cond='data:blog.pageType == "item"'>
<p>This is the post item page. Put your code here</p>
</b:if>
Now, where was I again? Oh yeah, the sign-off image.