I've always thought there should be some kind of service where you can donate leftover food, even already cooked and perishable foods.
Maybe through vacuum packaging and dry ice storage or something- some way to preserve the food long enough to get to a hungry person.
I feel like the logistics involved would be near impossible to action though :(
I have noticed that people in this country tend to cook too much at a time.. perhaps food conservation and sustainability should be taught in schools