Sandra and Peter Goleby have been collecting our spent coffee grounds daily since 2006, they sprinkle it directly onto their garden. They say it pretty much disappears into the soil after a bit of rain or watering.
It has a neutral PH level, it assists water storing capacity for the soil and has a residual natural insecticide called "caffeine".
Although it may not seem like a big thing, if they have picked up an average of 6 kgs per day, we figured they have saved around 8.5 tonnes of coffee becoming landfill!
Well done Peter and Sandra, "much respect" Mother Earth loves you for it.
P.S. Their house is the one built on the little hill! ;-)