I was physics/CS undergrad and did very well academically. I didn't really take notes much though. The strategy that worked for me was to read the book ahead of time, then the lectures were more to help digest material I was already familiar with. And for those giant auditorium-sized lecture classes, I just skipped class completely and only read the book. In fact I found taking notes to be distracting - how can I pay attention when I'm trying to copy everything down?