Penny stocks are one way to double your money, though it's fraught with risk, but there are equally shiny opportunities trading at the other end of the price spectrum, too. I call 'em "three-digit stocks," yet if they're anything like Berkshire Hathaway they can trade in the four-, five-, and six-digit range, too.

penny stock might not be a good buy simply because it's cheap, and a three-digit stock shouldn't scare you away just because it carries a hefty price tag. Handsome is as handsome does. Let's check in with the Motley Fool CAPS community to see which of the high-priced stocks below earn the greatest confidence from our investor-intelligence database:

Stock

CAPS Rating (out of 5)

3-Digit Price

Return on Capital, TTM

CARBO Ceramics (NYSE: CRR)

****

$115.13

15.5%

Caterpillar (NYSE: CAT)

****

$100.47

6.1%

OYO Geospace (Nasdaq: OYOG)

*****

$104.07

9.8%

Source: CapitalIQ, a division of Standard & Poor's; Motley Fool CAPS.

But just because these stocks are purring is no reason to jump into them blindly. Catching a tiger by the tail -- or a knife falling from on high -- can end up leaving you scratched and bleeding. That's why we recommend you use this list as a launch pad for your own research and analysis.

Highfalutin' honeys
As more oil and gas companies tap into harder-to-extricate shale reservoirs, they're increasingly turning to CARBO Ceramics, the maker of little ceramic beads that help prop open the fissures created to let the oil and gas flow. All the major oil services companies, from Schlumberger (NYSE: SLB) to Halliburton (NYSE: HAL), use CARBO's proppants, and 2010 marked the company's best year ever. Even the seasonally slow fourth quarter saw revenue rise 33%, as drillers increased their use of horizontal drilling

Yet therein lies the risk. Hydraulic fracturing, or fracking as it's called, is getting a lot more attention these days, and not just from drillers. Activists, politicians, and regulators are looking at whether the chemicals involved endanger the country's drinking water supply. The EPA, which regulates the process, thought the industry had stopped using diesel fuel; apparently, it was surprised to find out that 32 million gallons had been injected into wells, sometimes near underground water supplies.

For CARBO, however, it won't matter whether diesel fuel is used or not; drillers will need the proppant, however the fracking is conducted. With rig counts rising, the proppant maker is expecting growth opportunities throughout 2011 and even 2012.

CAPS member oilsands finds CARBO "perfectly positioned" to reap the benefits of drilling expansion, while swamp66 says there are "only a small handfull of companys in this market! this is the leader."

Drill down into the proppant maker's growth prospects by visiting the CARBO Ceramics CAPS page.

Digging deep
The inexorable rise in Caterpillar's stock is leading some to speculate a stock split is in the works. Shares of the heavy equipment maker have doubled over the past year, and global sales of mining and construction equipment drove profits to quadruple in the fourth quarter.

Caterpillar's expecting the global economy to match last year's 3.5% rate of growth in 2011, but China, India, and Latin America are likely to outpace North America and Europe. With almost two-thirds of Caterpillar's revenue coming from places other than North America, it's easy to see why management is upbeat about the future.

The improving situation has lifted many boats, with Deere (NYSE: DE) almost doubling in value and Manitowoc (NYSE: MTW) up by 75%. However, both of those companies are much more dependent on domestic growth, with 64% of Deere's revenus coming from North America, and half of Manitowoc's here in the U.S.

CAPS All-Star JakilaTheHun is pessimistic, believing that the mining boom will go bust soon. SO does sicilianmuse, who sees China construction grinding to a halt. Is there something to that? China just raised interest rates for the second time in six weeks to curb inflation, and Brazil saw consumer prices jump at their fastest pace in six years.

You can add Caterpillar to the Fool's free portfolio tracker, then dig up some nuggets of good opinion on the Caterpillar CAPS page.

Triple-digit titans
OYO Geospace provides the oil and gas industry the technology they need to find the reserves CARBO helps them frack out of the ground. It's not surprising, then, that its shares have also been on a tear, rising 170% over the last 12 months. Yet that kind of sharp upward mobility concerns CAPS All-Star BrianMotleyFool, who otherwise consider the seismic data equipment maker a very good company:

Breaking my rule on this one. OYOG is a great company with great prospects. Not one I would normally consider shorting. This is a pure trading call-the stock price has simply outrun reasonable near term prospects. I don't normally trade, so this call will probably bite me in the tush.

With momentum at its back, can the company continue climbing? Let us know on the OYO Geospace CAPS page.

Count to 10
These three-digit stocks might be on their way to even higher valuations. That's why it pays to start your own research in Motley Fool CAPS. Read a company's financial reports, scrutinize key data and charts, and examine the comments your fellow investors have made, all from a stock's CAPS page.

OYO Geospace is a Motley Fool Hidden Gems choice. The Fool owns shares of Schlumberger. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. 

Fool contributor Rich Duprey does not have a financial position in any of the stocks mentioned in this article. You can see his holdings here. The Motley Fool has a disclosure policy.