Class Websites
I find that class websites run by the professor are helpful, especially when they update them frequently with info about the course, class notes, and assignments. Unfortunately, I get distracted, lazy or both and forget to check the sites often enough. Like today, while checking whether there's an assignment in my statistics class for the Monday after Thanksgiving, I find out that there's an assignment that I was unaware of due in a few hours (D'oh!). Now if only profs would start using RSS feeds.