Dynamic blogroll based on RSS/Atom feeds.
I noticed that my WordPress blog had a Links widget for the sidebar, but it was static. I couldn't tell that someone hadn't posted anything since my last visit, so I searched for a widget that would make the Links widget more dynamic.
I found RSS Blogroll. It did basically what I wanted, but it didn't look quite right to me. I added a favicon option and also set the blog title to be a link.
This widget automatically grabs the latest posts from whichever blogs you want (enter the feed URLs into the widget setup) and displays those whenever someone visits your blog. Links can be displayed chronologically, and you can click on the link to either the other blog or the specific post that is new.
To aid in the aesthetics department, this widget displays the favicon of the target blog next to each link.
More information, including configuration and CSS tips, is at Some Blog Site