[ZK] My best excuse for not attending Uni lecturers was to claim I was boycotting them. This did not perturb my tutors in the least, acclimatised as they were to student politics. They didn't ask the reason.
And really, you know, it's about time they started using webcams to narrowcast the lectures anyway. I've attended several sessions at the University of Washington (where I'm not even a student) via this method.