Wow, this sounds like a great, yet simple, idea.

Next, Sonic Showers.

Oh now you've done it! I've got to go into shameless self-promotional mode.

I did look at this story twice and wonder whether I ought to add it to my Star Trek article...

hmmm, but does it rinse as well?

This is brilliant. We've already got aerators on our faucets, this sounds like a similar thing for showers.

Potable water is a major issue in 3rd world countries, I imagine this might be a big help.

Oh yeah, and I should mention that I clicked the story because it sounded like the sonic showers from Star Trek as well

Me too.