For Hydration I've always used water bladders. I started at first using the ones from Canadian Tire and other shops but really hated the fact that I was drinking plastic. After an hour or so the water starts to taste like the container as chemicals leech into it from the bladder itself.
Enter this product:
It has a special lining on the inside of the bladder so you don't get that wonderful chemical plastic taste to your water. Worth the $33 investment if you give a damn about that sort of thing.