Gold surges. Copper soars. Oil spikes. But no panic.

Copper at $6,000 per ton. Gold at $600 an ounce. Oil persistently above $60 per barrel.

The last time these key commodities enjoyed such a concurrent boom, inflation ruled, Ronald Reagan was headed to the White House, and the economy was in the tank.

So do today's run-ups in metals and oil prices signal trouble ahead?

Quite the opposite, some economists say. In a humming world economy, supplies of some key raw materials are struggling to keep pace with demand. That's no surprise. Likewise, investors, seeking profits at a time when stocks and bonds lack luster, are plowing money into silver and gold.

That means higher prices for everything from jewelry to aluminum aircraft parts. But for now, these represent a burden of added costs, not a crisis, economists say. The one potential exception is oil.

"I think it's clear from the economic data that this is a global economic advance taking place," says Dennis Gartman, editor of the Gartman Letter on investing. In such an environment, commodity prices rise, he says, and "why should they not?"

Of key concern is energy, where prices are now high enough that a further spike could put global growth in jeopardy. Rebels in Nigeria or a standoff over Iran's nuclear program are scenarios that keep some analysts awake.

In the long run, higher prices will drive new production and the development for alternative fuels. But in the short run, the oil market is tight, with little spare capacity in the event of a new disruption. And whereas a temporary scarcity of copper or titanium would affect certain products, an energy shortfall directly affects every business and household.

Oil prices have surged in recent days to nearly $70 a barrel, while US consumers are reeling under a government forecast of $2.62 or more per gallon of gasoline this summer. Yet for a year or more, the US and global economies have stayed buoyant in the face of rising oil costs. It would probably take a major price shock to change that, analysts say.

Even as energy prices help guide the economy's path, other commodities tend to react to economic strength or weakness. And lately, the pattern has been strength.

"All the industrial countries are riding the same growth train," says Jason Schenker, an economist who tracks commodities at Wachovia Corp., a banking and investment firm based in Charlotte, N.C.

This adds to fast-rising demand from developing nations from India to Brazil. China has become the biggest factor behind rising demand. It now accounts for 25 to 35 percent of the world's use of aluminum, copper, iron, steel, and coal, according to research by Morgan Stanley.

Next to energy, the hottest commodities have been metals, used for industrial as well as investment purposes.

Gold and silver have glittered as it becomes easier for small investors to jump on the bandwagon. "Exchange-traded funds" now make buying those metals as easy as buying a share of Alcoa. (The aluminum company just reported a doubling of profits over the past year.)

The commodities boom hasn't reached all sectors. Fats and vegetable oils fell over the year ended in March, according to World Bank data. But for many basics, prices are up. Sugar prices have soared, for example, thanks to rising demand for use in alternative fuels.

All this adds up to the biggest commodities boom in more than two decades.

Typically, cycles in metals can last for years, and eventually mining and extraction companies feel the confidence to expand production. Analysts say that should happen this time, in general, for everything from the aluminum in aircraft to the nickel that's increasingly used in batteries for hybrid cars.

In the meantime, the high prices are affecting businesses and consumers throughout the economy.

From a simple wedding band to a titanium watch, many goods will cost more.

At Firefly, a jewelry and gift shop in Boston, owner Martin Checkoway says vendors of silver bracelets and necklaces have been restrained in their price increases. "There's only so much the end customer is going to pay," he says. But in recent weeks some artisans have raised their prices by 5 to 10 percent, he adds.

Raw materials also cost more on construction sites and factory floors.

And from Iowa to California, metal prices have gotten so high that one cyclical form of crime has returned: theft from scrap bins. Marty Forman, a metal recycler in Milwaukee, takes the ups and downs of his business - and the risk of burglary - in stride. But he guesses the price trend will be upward as demand keeps growing.

"The bottoms will not be as low" in future cycles, he says. "There's only so much metal in the ground."

The metals boom has also given a boost to some commodity-driven economies, such as Canada, and roiled others, such as Peru.

"They've seen tremendous growth in the economy but not much in terms of being able to filter that down to the poor," says Mark Johnson, who manages the USAA Precious Metals and Minerals mutual fund. That goes a long way toward explaining the rise of populist politics there, he adds.

Even as the commodities boom alters the dynamics of elections and wage bargaining at mines, it isn't necessarily fueling broader inflation in today's more service-driven economy.

"A lot of it can be absorbed in terms of the macro economy," says Mr. Schenker of Wachovia.

Commodities are drawing plenty of attention from investors, however.

Some are "gold bugs" worried that the dollar could fall in value, that stocks could tank, or that inflation will return.

Others are simply looking for alternative places to invest at a time when neither stocks nor bonds are soaring. The "yearn for yield" has fueled a range of other investments, from hedge funds to real estate.

Commodities have a reputation for risk. But recent research suggests that futures contracts on commodities have historically offered similar returns as stocks for a similar level of risk. And because they don't necessarily move in sync with the stock market, they can be useful in diversifying a portfolio, say researchers Gary Gorton, of the University of Pennsylvania's Wharton School, and K. Geert Rouwenhorst, of the Yale School of Management.

Other avenues for small investors include mutual funds focused on commodities or gold stocks.

Mr. Johnson, whose precious metal fund has posted returns of more than 80 percent in the past year, also sees diversification as the key reason to buy. By putting perhaps 5 percent of one's assets in such a fund, investors will likely reduce the volatility of their portfolios.

But he adds a word of caution: "This is definitely a risky category."