Soshiku is the best homework assignment tracking web service that I have discovered to date. The interface is straight-forward and elegant. It has options for creating different classes and assignments. Each assignment has a title and due date, and can contain notes, file attachments, and a task list. It also has some collaboration features, which I have personally not taken advantage of, but would be useful for group projects.

Remember the Milk is a to do list web service. There are some other online to do lists out there, but they fail in comparison to Remember the Milk. RTM is making a great attempt to take on the internet. Any good daily, task/communication oriented web service should have ties into many other web services. Like Twitter, RTM has many different means of connecting and communicating with it over the web.