Camelback pioneered the hydration bladder and pack. Extensively used by our soldiers in Iraq and outdoor folks everywhere the bladder and pack in its various forms has redefined how we drink on the go. I have used various generations of the product as it has evolved.
For longer runs/hikes 4 hours plus I use a Patagonia Endurance Pack with a 70 oz. Camelback Unbottle inside.
For 1-3 hour runs I have been using a Camelback FlashFlo belt pack with a 45 oz bladder inside. I find that the excellently stable Patagonia Endurance is not much fun on the back when running fast.
After trying belt packs with bottles I find the no bounce FlashFlo to be an excellent way to carry water, and a few supplies in the two back zippered pockets, without ever noticing it is even there. The two side/back straps allow you to cinch down the pack as you draw down the water without tightening the waist belt. An over tight belt can constrict breathing, especially going uphill. Never any bounce even when full. The bladder is easy to remove and put back in, helped by an elastic port on both sides. The drinking tube clips to the very breathable soft mesh belt on either side. The only thing lacking are pockets on the belt for energy gels, GPS, etc...I used the pack on a 50 mile road bike ride and found it very comfortable there too.
Camelback also makes the Better Bottle which I have had for a year now. This polycarbonate bottle has a flip up drinking nipple of the same material as the those on the bladders. Flipping up the nipple activates the flow. A straw below the cap allows drinking without tipping the bottle back. The Better Bottle is relatively heavy and of course stiff. Great for work or travel.
In my Camelbacks I have been using their Elixer electrolyte tablets. Not too sweet or sticky. Nice taste and a toss up in terms of preference with the Nunn tablets I previously wrote about.
At OR Camelback introduced a 22 oz Performance version made of soft, light polypropylene (see picture above). Most bike bottles are made of LDPE which imparts a taste to water. Camelback claims, and my initial testing confirms, there is less taste with the polypro. Same nipple as the Better Bottle but the spout doesn't fold down onto the bottle. Flow is started by an easy twist of the lid. This is a great bike bottle, soon to followed by an even lighter Podium version.