We ditched the stroller this year, too. I already wore a medium-sized back pack (REI day pack that actually came with some luggage) and carried extra water, but we kept snacks/water for kids in the stroller. This year I bought them each a Camelbak pack which fit their water, snacks, and light jackets. I put a water reservoir in my back pack for myself and carried the usual snacks, sunscreen, necessities, cooling towels, and poncho. Giving them each a Camelbak was the way to go! I wish I had ditched the stroller a year sooner! No one complained once about having to carry the bag/weight, and they were DEFINITELY hydrated (read: extra bathroom trips).