Recent Modified Posts
Sometimes I update earlier posts. Although WP has a field in the posts table to record the last modified time, it is not easily access or use to show updated posts or to display them in a list form. The alternate way is to modify the time-stamp of the post itself, but that would change the permalink and make external referral a big issue.
As a result, I have written a few lines of codes to pull together a list of recently modified posts and place it on the sidebar to the right. Check it out from time to time to see more info I put in previous posts.