kegsbytheriver wrote an answer about Osprey Packs Momentum 34 Backpack - 1920-2040cu in on April 14, 2011
There isn't a traditional sleeve for a hydration bladder, but you can still use one. This pack allows you to tuck away the shoulder straps; they're connected on the top and bottom via quick release buckles. The quick release buckles can be detached, and a hydration bladder can be inserted down into the space where the shoulder straps would be tucked away. Then, reattach the quick release buckles, and you have a hydration pack. This space is similar to the Talon series' hydration space. It might not be the most stable setup, especially if you're not using the rigid Opsrey Hydraform bladder, but it's better than nothing. I was pleasantly surprised when I figured all of this out because I thought I would have to slip the hydration bladder into the laptop compartment.