+1 on ditching both the Camelback and Nalgenes. You don't need that much capacity and both containers, even when empty, are heavy.

Other possibilities--Smart Water bottles are durable and narrow enough that the 32-oz. size fits even the narrowest pack pocket. They last a long time. I get the 22-oz size for the convenient flip-top cap and the 32-oz size to hold the water.

Gatorade or other wider top bottles are good, too, if you want to mix drinks with powdered drink mixes. I now use the kind that Kroger "Simple Truth" organic juices come in, as they don't have the Gatorade smell (which I hate). They weigh a bit more than soda or water bottles but far less than a nalgene.

For either of the above, I'd take an extra cap. They do have a tendency to get away from you and roll down the hill to an undisclose location! It has happened to me half a dozen times.

For camp water or dry days, I'd get an Evernew (if you can find one) or Platypus 2-liter container, as Pika suggested.. You'll rarely need one on trail and when empty it will roll up and take hardly any room in your pack. Evernew containers have the cap attached, so no danger of losing it, and are compatible with the Sawyer Squeeze filter. (That and the aftereffects of the Japanese tsunami are why Evernew bottles are so hard to find.)

An important part of trip planning is to study maps and trail guides for the distance between water sources so you can determine how much to carry each day. Water is heavy! If water sources are frequent, I carry only a half-liter at a time. If available twice a day, one liter at a time. If it will be dry all day, two liters. It also helps to "camel up" by drinking your fill before leaving the water source.