This was a project I started around the year 2008. It was a to-do list with a four column interface: 1) yesterday, 2) today, 3) tomorrow, 4) unassigned. You could easily create, edit, and check tasks and drag them around the different columns and had features like creating recurring tasks and more.
This was my first larger Ruby on Rails project and I hosted it on a Linode Linux box with a MySQL database. It has since been abandoned and is not accessible to the public anymore.