I wrote an online quoteboard from scratch. Using only my own code makes it lightweight, and I like being able to customize every detail.
After 30 minutes planning and around 30 minutes of quick PHP/Mysql coding, I had a functional version of the site:
Each quote also has a page where you can discuss it. Using xmlhttprequest, I added AJAX voting buttons that don't require a page refresh!
Today, I added some styling, which took a while, but looks nicer: