Blogger expandable post summaries
http://hackosphere.blogspot.com/2006/11/selective-expandable-posts.html
This hack avoids showing the "Read more..." link even if there is
nothing more to read. (The Blogger help article had this problem.)
However, this hack still has this problem if you click on the "Newer
Posts" or "Older Posts" at the bottom of the page.
Here is what's put in the post template:
Type your summary here
<span id="fullpost">
Type rest of the post here
</span>