>more efficient shower heads that use less water but provide the same cleaning,

I think a lower flow but high pressure might be useful here; perhaps supplement normal water pressure with an electric pump. Another possibility is low flow with a trigger that lets you turn on high pressure/flow when you need it.

You can already buy shower heads that claim to save 30% water, by mixing more air into the water stream.

But then people just hack it so it stays on high flow.

Why would you do that - when you have to pay for the water and energy?

> The transportation situation, of course, is more expensive and tedious to fix,

I just got back from a trip to Portland. Free public transporation in the city center! Whoa!

As one of my professors once said, one the big reasons public transportation won't work in the suburbs (car-owning individual attitudes aside) is usually you can't walk through backyards (e.g. no regular street/crossover grids).

Ralph Roberts, founder of Comcast, once said that Americans want three things "TV, sports, cars". Take away any of the three and you have a problem...

I agree that we're not going to break Americans of their love of cars. Indeed, the love of cars is spreading! One of the reasons gas is getting expensive is that people in China love cars, too!

What could happen, though, is that cars will become a luxury item for more and more people. That's slowly happening now, as oil gets more expensive. Cars will get smaller. They'll emphasize efficiency. They will still be bought, but will be driven less and less. Perhaps there will be one car per household rather than two or three. A lot of cars will just be for show: They will look really fast, sitting there in their beautiful garage.

Eventually cars might end up where horses are today -- a few high-tech racecars, some recreational cars in upper-middle-class garages, some working cars in poor areas of Third-World countries, and a rich literary tradition -- tales of the wild Carboys and their lives on the highways of 1960s Las Vegas. (Come to think of it, we've already got the literary tradition.)

Or, cars might just become passe. People's tastes can change on a dime, if the price is right. Some of us were hip enough to hate SUVs before it was cool [1], but everybody is starting to hate them now. Large numbers of people used to be really into horses, square-rigged sailing ships, steamboats... but once gas got cheap there was no turning back.

Or maybe somebody invents Mister Fusion and we're all saved. Or it turns out that plug-in electrics plus breeder reactors plus solar panels make the car culture work for another two hundred years, which is rather more likely but hardly guaranteed.

[1] Or, rather, before hating SUVs became so mainstream that it was no longer hip. Perhaps the hipsters of the mid-21st century will all own enormous nuclear-powered SUVs.

The typical car carries 3000 lbs of car and less than 200 lbs of person. Even a fully loaded car with 5 adults is probably 20% payload, 80% vehicle. There's a lot of room for more efficient transportation without qualitative changes in how it's carried out.

The main issue here is I don't want a compromise in my shower. Not for hygienic reasons, that's a practical matter and can be addressed as such, but because hot baths/showers are a mark of civilization, of the fact that we live in the environment we choose.

The transportation problem at least can be solved. Besides public transportation I think one solution would be to think local more. When hiring somebody I'm factoring in their commute time - it influences a lot of their long term job satisfaction.