I have a big fanny pack (Eagle is the brand) that has the side-adjustments. I put a 100 oz bladder (Platypus) and hose in it, and run the hose around front.

I also have a 100 oz Camel Back, but in warmer weather I prefer the fanny pack! Some of the newer models are probably less "hot" on the back than mine ... (I think it's a Rogue? came in blue or mango when I got it...)

Both are big enough to carry a granola bar, and my wallet, keys & cell phone as well! (the fanny pack has more room!)

I only use water in either of these, and gatorade (or carrot/pineapple juice) in a gatorade bottle on the bike if the ride is going to be longer than an hour or so. I have found that the gatorade bottles (24 oz, with the green and orange sport top) are the easiest to use on the bike. They slip in and out of the cage easily, and opening the bottle itself once it's out is a simple twist of the lips &/or bottle! I never use "official" bike bottles anymore ...