I was on the verge of chucking the latest gift-catalogue that arrived through the post this morning in the bin, but had a flick through it to amuse myself and came across this:
http://www.initialideas.co.uk/itemdetl.php3?itemprcd=9400
I'm not sure just how "easy" it would be to lobb off the bottle top, but the advert suggests that it's "simple". Anyway, I thought that it might prove of amusement (I think that Amadeus Gould mentioned this in an earlier thread).
NB I shan't be rushing out to buy one though - good recipe for a law-suit IMHO.