Thanks Guys,
My water filter is made almost specifically for the hydration pack, so... I'm sorta committed to it for now. I have a milspec canteen with cover and strap... [i]and pinhole[i], but I bought the "Frontier Pro" filter. It says I can use it with water bottles, but I would like to use the hydration pack. Anyone doing it with a "classic" backpack and a "camelbak" style pack?
I may just try to rig it to the outside of the pack. Seems like there ought to be a more elegant solution. I have thought about wearing it on the front, but have not tried that yet. Took about a 4 mile walk with it and my dog yesterday. She and I finished about half the bladder.