How to create expandable post summaries..
With this trick we can choose to display an arbitrary amount of text from the beginning of each post, as a teaser for the whole thing. Then users who want to read the rest of the post can click a link to see the full text. This is handy if you have lots of long articles all on one page. Note that we'll need to have post pages enabled in order to make this feature work.
There are three ingredients that go into this feature: conditional CSS, a "read more" link for each post, and a modification for the posts that use this feature.
I have try the trick to my houseblog.. It is simple and quite good to make our post more attractive to reader..
Try the technique from eblogtemplates , technade, bloggerhelp, Blogbuster

Nice post bro :D I try this one and it's successfully working on my blog site.
A Simple Kind of Something By the way, I want to exchange links with you. I already added yours its under in SEO | Blogging section.
I hope you can add mine. Thanks a lot for the great article of yours.
More power to you :D