My students' Activity Books

This school year started with a new idea of teaching English. My students are good internet users and spend much time online networking or just chatting with friends. I decided to use their online time productively.
Once a week the students have a task which is closely connected with their educational programm. They write messages according to the topics they discuss at the lessons. More over they prepare some tasks for spelling and grammar practising. After they offer the exercises to their classmates to do for a mark etc
So, really there is plenty of space for teacher's creativity.
Hope it works.