The calendar is just in general a good way to keep a schedule and make people and yourself aware of dates and times coming up.
Knol would be a good way for students to look up info and or to express info the know, as an evaluation. The teacher could then check their posts for accuracy.
Picasa would allow you to save, view and use photos in the class. It seems alot like flickr, but through google.
igoogle, is a great application, but I really only see it as being useful for the user or the teacher. Relaying the information the teacher the information they want on there google homepage. Again I like it alot especially how customizable it is, just not sure about applying it in a class.
Maybe somebody else has some tips or possibilities?
Seeyah Next Time,
Cagle