Link Within is a simple to install and automatic Blogger widget that will display 3 thumbnails and titles to related posts under ALL of your posts. The nice thing is that it is automatic; nothing to do but install it, and each time you or a visitor gets on your blog, the Link Within links change, so no one sees the same link or thumbnail every time.
Go to www.linkwithin.com
and follow the easy instructions, and it will place it automatically on your selected blog. Go to the Design section of your blog and move the widget directly under "Your Posts" and you're good to go!!
This little golden find has been wonderful to get my visitors to view other similar posts instead of taking the time to look under my posts related under the "Tags" - very helpful!!