My first impression is that I could use it to wash maybe three shirts at a time, and there is no way to actually gets sufficient energy to do a good job as easily as shown in that video. If you could hook it up to some kind of bicycle-pedal-style drive though...
No doubt. Triple the size and rig it up to a stationary bike and you might be on to something.
This was my thought as well. This washer is supposedly about half the size of a regular washer, but the guidelines are that it can wash 1 pair of jeans OR 6 t-shirts OR 8 boxers at one time. That seems a bit smaller than half a regular washer.
Still, it's a cool concept. I could imagine keeping this in the shower if you have a large walk-in shower, throwing underwear and socks in there, and running it once every other day or so. Could really cut down use of a washing machine to every-couple-weeks type work of larger items like jeans, sweaters and towels. I could also see this being really convenient if you live in a small apartment without a washer and dryer and have to rely on the laundromat (like I did living in Manhattan). There the savings would add up substantially sooner, as you're eliminated lots of $3-$5 loads.
Here's their official site:
http://www.yirego.com/And Indigogo:
https://www.indiegogo.com/projects/drumi-the-foot-powered-washing-machine-design-green#/But a bike powered equivalent that could hold the volume of a regular washer and clean your clothes after 10-15 minutes of exercise? That would be awesome. I tried searching the web and could only find a few homemade contraptions like something a crazy prepper might have.