Dagon Design has a great plugin called Other Posts from Cat. I like this plugin both from a bloggers and a readers perspective. It is nice to get a listing of related posts which makes it easy to find more information. When you are viewing a specific posts this plugin lists the latest posts from the categories the current post belongs to.
In the built-in options page you can choose the number of posts to show, set the header text, choose to show the post dates and more. The latest version also has an option to show recent posts from all categories the current post is in.