Interesting way to handle power generation, not exactly water efficient if using a faucet; but in a power outage the water usually runs for most people. And all you'd need is a hydraulic turbine and you could even use this for generating power via wind, or even biking. Like the fact you can replace the batteries yourself when/if they go bad/use them yourself as AA's.

Interesting but a bigger version/product that can provide power for a small home set up (some LED lights, a fridge, a laptop) would be really useful for developing countries.

The ability to attach one of these to a bath / shower / sink drain pipe would result in power from waste water - amazing!

Why not use the water main running into the structure to generate electricity. The potential energy is already made available by raising the water to the water tower. It may impede flow somewhat, maybe not.
If I recall I saw a prototype of this somewhere.
Thoughts?

PVs pump well water up to a water tower. At night the flow from the tower powers and provides water.

To the earlier commentors: You can't get something for nothing. 746 watts= one horsepower, which equals 550 pounds of weight, falling one foot in one second. The amount of power from water pipes, drains, etc., even in the flowing stream, is no doubt like 2 watts per hour, if that. It's probably "milliwatts", which is why the video doesn't mention the measurements. Considering a "fridge" takes thousands of times that amount of power...!
You could run a charging station in Africa, by pouring five gallon pails of water into a funnel, through the generator/impeller, into a second bucket, which is then lifted, repeat. But, you'd get more power faster, sooner, by simply hand cranking a small generator. A treadle-powered device would cost less, and charge faster, and weigh less in a backpack than this 'gizmo'.

Here's something for all of you sailors out there.

It could be used to charge the E-meth pipe as seen on Saturday night live. but I could see this as a handy item on a john boat to help charge, fish finders and lights... I like it !

Two comments that I'm sure have already been thought of... 1) Why float the thing? That places part of the turbine out of the water and nonfunctional. Would it not be more efficient fully submerged? 2) I sail and would like to tow such a device to charge the deep cycle batteries that power the trolling motor I use as a "kicker". I now use solar panels, but I can't (or don't want to) fit enough of them on the boat. A larger version of the Hydrobee that runs power up the towline to the batteries would be great!

Would be great if you could plug your device directly into the line tethering the hydrobee in the water.
For instance so you could attach the hydrobee to a tree, drop it in the water, and then plug your device to the line tied to the tree using, say, a USB plug.