We'll be going to DW in June with 6 adults. I just bought us all Camelback/Platapus (you know, 2 liter water bags with a sippy tube) back packs at Sams Club for $18. Has anyone ever traveled around DW with a Camelback and was it handy or a pain? These have wide mouth openings so they can be washed easily if water flavors (tea, kool aid, etc) are added and ice can be added also. I figured if all else they could be used as backpacks if the water part didn't work out. Any ideas?