Katadyn Hiker Pro. I got a small adapter that connects right into the hose of my Camelbak so I can filter water without even taking my pack off.
Works great.
Joe,are you filtering contaminated water out of the camelbak? <img src="/ubbthreads/images/graemlins/confused.gif" alt="" />
And if so do you have a backup reservoir or just clean it when you get home?