I agree entirely with Clare Fox's article ( TES 27.02.04 ) on the importance of debate as a means of inspiring sixth-formers beyond the confines of the curriculum.
As a sixth-form tutor I have found the following strategies very successful:
a) Recording BBC's Question Time, Newsnight or Andrew Neil's This Week (excellent), and debating the issues raised.
b) Encouraging students to listen to Radio 4's The Moral Maze (frequently starring Clare Fox).
c) Taking a group of students to BBC Question Time and getting them to ask a question (great for the CV).
d) Organising conventional debates with wacky motions such as "This house believes that it's better to be a scientist than a streptococcus"
Through a process of relentless intellectual sparring we may produce the original thinkers that this country so desperately needs.