I have the same problem - I want to bring water, but not the bulky backpack. I think I have found the solution, but will have to wait until my September trip to test them fully. I first saw these gadgets in an Eddie Baur catalouge for about $20 each, but then found some in Wal Mart in Sporting Goods for around $4 - it is a water bottle holder that hooks to your belt loop. There is an adjustable ring that slips around the top of the water bottle, and then a short strap, and then one of those clips like rock climbers use to hook onto your belt loop. I bought one each for me and DH - can't wait to see if they work!