If you were rich, you wouldn't give a damn about the gas mileage on your yacht. And I think that's kind of how it should be (in a capitalist society).

Well, evidently a lot of millionaires would agree with you. And perhaps the reasons I disagree with you on this are some of the many reasons I'll never be a millionaire (without hyperinflation, anyway). But I think that just because something's possible, that doesn't make it a good idea: even though the market happens to have priced (a) your salary and (b) oil at relative levels such that you can afford to use a lot of gas, doing so is still pretty irresponsible.

Advocating the guzzling of gas because it's affordable ("I can so I will") seems no different from advocating that the largest kid in the school can beat up the others because Nature has afforded him the strength to do so, or that the largest military power in the world can beat up the others because Manifest Destiny has given it the strength to do so. This is not, of course, an exclusively US attitude.

Now, as far as running out of oil goes, I don't think it'll happen anytime soon, or prices would go up since there would be a diminishing supply, and usage would drop.

That, sadly, would require some link between 10- to 20-year forethought and today's oil pricing. No such causative link exists. Oil company shareholders, and thus oil companies themselves, simply do not care about issues on that sort of timescale.

Peter