Startup Idea : Twitter app for sharing surplus food to the needy

Whenever we eat at restaurants etc we find that there is always surplus left at our table.Same time we find that there are people on streets or orphanage etc who have a scarcity of food.We can make a simple smart phone based app or twitter app which will allow a user to tweet with a hash code that he has surplus food.Along with this tweet he will also send the location.This tweet will be accessed by volunteers in that location who would collect this food and distribute to the needy person.