I've not been for a while, so am not sure if this is still the case, but at the Eden Project on Cornwall, there is a cafe where one simply helps oneself (to tea, coffee, biscuits, cakes, scones, sandwiches, etc) and leaves the appropriate amount of money. No one monitors this. I was amazed. Needless to say, we were scrupulously honest with our payments, but I daresay that isn't the case with everyone.

The Eden Project is a curious place. It's what happens when hippies have too much money. Still, they do some cool things. They had some great concerts recently (including Pet Shop Boys, my all-time favourite group). :)