Gmail in the Classroom

I am a substitute teacher. I have used Gmail to communicate with the teacher I am subbing for  the evening before the class. The teacher has sent me the lesson plans to review so I can ask questions by email before she/he is unavailable the next day. I also think using Gmail would be beneficial when a student is absent so you could send them the missed assignment. Instead of making paper worksheets, students could send a gmail to the teacher with the answers to the questions on the worksheet. The teacher could also create groups and or labels for their different classes that they teach i.e. algebra I, Algebra II, Trig etc. The class sylabus could also be sent to students via gmail so they would be able to creat a folder for each class and not loose it during the semester.