Web-based Note Taking
mynoteIT is an extremely powerful utility for any student at any grade level. You can store all your school information in one place, and access it anywhere in the world instantly.
Uses PHP, some AJAXy stuff thrown in. Very straight forward, clean feature set. Student and class centered. Groups are created using school/class/teacher/time boundaries. Includes basic calendaring. Editing is done in a basic box using FCKeditor (my personal fav, BTW) with an AJAX wrapper. There is some stuff to glean from this:)