We'll be traveling with two toddlers so we'll need some diapers, wipes, sunscreen, camera, autograph book, possibly a change of clothing for each, small wallet for ID cards, etc, and ponchos. I do intend to bring the small cooler bag (that we bring everywhere) to hold two sippy cups and some water for DH and me and maybe a snack or two in addition to the "main" bag" I never wear backpacks and although they seem great b/c I could be hands-free, I'm worried it might bother my back after a few hours and that it would make my back all sweaty in the May heat. My other option is a medium size cross body. Again, this is not a style I usually wear, but seems more practical than my usual diaper bag that I either carry on my shoulder or clip onto the carriage. Just wondering about what works for other people who travel with toddlers.