The website Mindhacks is a constant source of stuff that is entertaining and informative. Here is a contribution that deals with exactly that combination: learning and fun.
One of the many negative things about the misconception that education is about transmitting content is the idea that any fun you have is taking time away from proper learning, and that 'proper learning' shouldn't be fun. Learning can and should be fun. This is not just a moral position, but a scientific one too. Read on