Berkeley economics professor Robert Frank is worried about consumption. He's written a book called Luxury Fever, which addresses the topic. I've also addressed his arguments here.

It's not common that a left-of-center economist endorses nixing the income tax in favor of a consumption tax, but that's sort ofwhat Frank does (.DOC). He wants to see a graduated consumption tax:

Our problem, in short, is the incentives that guide individual spending decisions are much like those that generate military arms races. Spending less would be better, but only if everyone did it. [...]

We can do this in a powerful yet unintrusive way by scrapping our current income tax in favor of a more steeply progressive consumption tax. Such a tax would be straightforward to administer: Each family would pay tax not on its income, but on its total spending--as measured by the simple difference between its annual income and its annual savings.

Because the rich are able to save and invest so much more than the poor, fairness would require that tax rates on the highest spenders be significantly higher than the current top tax rates on incomes. But even if tax rates were set to raise no more total revenue than under the current system, a consumption tax would have a profound effect on specific purchase decisions.

Consider the choice between a Porsche 911 Turbo ($105,000) and a Ferrari 456 GT ($207,000). The Ferrari buyer is currently willing to spend $102,000 more for his top-of-the-line purchase. But with a top rate on taxable consumption of, say, 70 percent, the effective premium to buy the Ferrari would be more than $173,000.

Because the consumption tax offers an exemption for savings, the Ferrari buyer would have a strong incentive to invest a little more in the stock market and a little less on his car. If he buys the Porsche, his outlay--including the tax--will be $178,000. In return, he gets a car that performs just as well as the Ferrari and, assuming others have responded similarly, just as rare. The tax preserves the aficionado's ability to indulge his passion for sports cars while increasing his savings.

It's a really interesting concept, though I have two problems with it:

1. The trouble with sin taxes is that the government profits off what people shouldn't do. The cigarette tax, for instance, had the somewhat mutual exclusive goals of raising money and discouraging smokers. The problem is that if smokers are discouraged, less funds are raised. This has the same problem. If it leads people to purchase less luxury goods, then we face budget shortages. Eventually you might have to raise these taxes so high that few can afford to spend their own money on anything but the necessities, which would deter innovation. That brings me to the second problem.
2. As agitated as I get with overconsumption and as much as I can see where Frank is coming from, the wealthy's extravagant conspicuous consumption on things technological (for instance) have a positive affect as well as the negative ones that Frank describes. New technology tends to work itself down the economic ladder. They pay outrageously high prices for not-yet-commonplace technology (say HDTV five years ago). That gives the manufacturers a profit, which allows them to produce more and lower the price and make money on volume. Once upon a time computers cost $3,000. The people indulging in luxury purchases back then were instrumental in getting to the point that computers cost a fifth of that. Penalizing the early purchasers would have slowed down growth of the industry, I'd think.