AZskibum, while I like the idea of being able to recharge my cell phone or other batteries while on a hike I am not sure that it is practical. Given the nature of much of the terrain here in the North East, there is not a lot of water available for this type of charger and the time needed to charge is too long - consider standing around for 2 hours waiting; can't leave the phone and charger. Tthe location may be a nice one but only if you are camping out (say for the night) would this make sense. The additional weight is also a concern, traveling lighter is always better. If I had a vote I would be looking for either a flexible solar blanket that can charge as I go or a hand cranked generator to provide recharge power. The other option would be to take advantage of the nature of hiking: using the energy that walking generates to trickle charge your devices.
"How much flow of water is needed for the turbine to function properly?"
According to the Hydrobee site, "Flow of only one gallon per minute will charge the battery. Water flowing at a fast walking speed (about 4 mph) has enough energy to charge the 6 AA batteries in the Hydrobee can in about 2 hours."