Most coffee shops have a little sign saying that if you ask for Fairtrade beans to be used for the production of your mug of coffee, it will be done.
I plucked up sufficient courage to do this in a branch of well-known chain last Saturday. I am pleased to say that the instruction was somehow communicated down the chain of three people who took my order, processed my money and made my coffee. So, at the end, the young lady who gave me my coffee said "Fairtrade Latte, sir". Great.
(I watched carefully and I didn't notice any different bags or sources of coffee beans being taken out specially for my coffee, but I'll let that pass - I'm far too cynical).
One thought though. Why don't they just go the whole hog and give everyone Fairtrade beans and have a little sign saying:
"Please ask if you want unfair trade beans" ?
Job done. Sorted.