I've skipped lectures in the past. However, it's not entirely rebellious as usually I have had decent reasons. Sometimes though, the reasons have been completely stupid. For example, back when I joined the university film-making society last year, I skipped two lectures just to turn up at a shoot for a two minute short film. The irony is that although those lectures were unimportant anyway as I still passed both modules, the film we made still isn't finished...
(I tell a lie, it is, we just can't watch it because we need an old style projector since we filmed it using Super-8 and we don't have a projector to view the film on...)