Nopax, they already have hoses like that at many gas stations over there. A flexible sleeve fits over the filler cap and collects any escaping gas as you fuel.
All very well, I suppose, if you're that keen on saving the whales and things, but what I want to know is - I've paid for all the fuel I dispense, vapour included - does the pump give me a refund for the recovered gasses?
Incidently, I used to work for the Environment Agency here, I was very surprised when, on my first lesson, I was told to dump the fuel on the ground. Never got round to looking into the official position on that ('cos I have a life) - anyone know what the rules are?