Did this one year with all of our leftover food, snacks, packs of gum, brownies, etc. It was our last night and we loaded up a backpack with everything we weren't taking home and started walking up the beach toward Alfred's. I found that I got the biggest surprised reaction from the people who were trying to get "money for food" when I would pull a hand full of snacks/food out of my bag and offer it to them.
And not to hijack the thread, Negril is as safe as you make it. As long as you listen to all the good advise here and use common sense you should be just fine. Have a great trip!