Some companies are obviously great investments -- in hindsight. Yet for every stock out there screaming "buy me," others simply give us a nudge and a nod. How can we tell tomorrow's obviously great investments from the thousands of pretenders?

The stars' walk of fame
On Motley Fool CAPS, these opportunities can be found among our four-star stocks. In CAPS' proprietary ratings system, they rank higher than most of the other 5,400 starred companies, but they're just shy of superstardom. While all the attention might be focused on their five-star peers, we can sift through CAPS to find four-star firms approaching greatness. Here are a handful of four-star firms approaching greatness.

  • Excel Maritime (NYSE: EXM)
  • Hansen Medical (Nasdaq: HNSN)
  • Philip Morris (NYSE: PM)
  • Procter & Gamble (NYSE: PG)
  • Silver Wheaton (NYSE: SLW)

Some of these names might surprise you. For example, Procter & Gamble is a household consumer goods giant, owning power brands like Old Spice, Ivory, and Tide. Almost great? Even familiar names can still offer some of the best opportunities. Perhaps we've just forgotten the potential they still hold.

Philip Morris is also a global presence whose cigarette business casts a long shadow without the same litigation concerns as Altria (NYSE: MO). It owns more than a quarter of the international market share for cigarettes, excluding China, and has at least a 15% share -- and in many instances substantially more than 15% -- in 90 markets. However, the 165,000-plus CAPS members chose these companies as less obvious sources for tomorrow's great buys, so let's see why they might merit your attention.

In the sight of greatness?
The Baltic Dry Index (BDI) is a closely watched barometer for signs of economic growth. Measuring what it costs to ship dry bulk goods around the globe, a rise in the index is seen as positive because it suggests there's lots of demand. A BDI in freefall, as occurred in 2008 when it lost 90% of its value, is seen as an ominous indicator of contraction.

You'll find the fortunes of many shippers like DryShips (Nasdaq: DRYS) and Excel Maritime tied to the index because of such apparent correlations. If that's the case, then shippers are a horrible place to be right now because the BDI looks like it's gone a few rounds with the 1980's Mike Tyson. After staging a brief rally this year, the index has fallen sharply over the past few weeks, dropping nearly 30% since the end of May.

But there's more to the equation than simply demand, as the number of ships available to carry cargo also plays a role. China, for example, has almost doubled year-over-year production through April at its shipyards and is looking to become the world's biggest shipbuilder by 2015. CAPS member AQ1USN says that country will be the key to the industry's -- and Excel Maritime's -- rebound.

Shipping is essential to the economy. China demand for raw materials will return to prior levels and exceed them. This will provide the opportunities for the shipping industry to ride the upturn.

On the shoulders of giants
The hold that was placed on hospital capital expenditures during the downturn crimped the ability of medical device makers like Hansen Medical from getting their machines purchased. While waiting for the freeze to thaw, they've now got to keep an eye on what's happening in Europe to ensure that business doesn't fall off.

The financial crisis in Greece, for example, had the government scrambling to come up with a plan to pay the billions owed to drug and medical suppliers. The country is skirting default and Spain looks as though it's on shaky ground too. Despite the EU making available hundreds of billions of dollars to bailout these troubled countries, fears of a domino effect of sovereign defaults run rampant.

Hansen makes medical robotics to assist in the placement of catheters. Through 2009, 30% of the systems cumulatively sold have gone to Europe. A new financial scare there would put the brakes on any new spending. Yet 95% of the more than 500 CAPS members rating Hansen believe it will outperform the market.

Insert your opinion on the Hansen Medical CAPS page and let us know whether Europe's wobbly knees will impact the device maker.

A big opportunity
 Silver Wheaton's ability to swing a sweet deal from GoldcorAp's San Dimas mine has swayed some skeptics into believing it will continue buffing its sheen as an attractive investment. CAPS member rivermanco sees the silver miner as having a three-prong attack on greater growth.

[Silver Wheaton's] graph shows it is over sold at the moment. It has great potential from three directions: (1) an inflation hedge, (2) a shelter of value conservation in a nervous market and (3) a great potential as Asian economic expansion puts demand on industrial silver.

A great opportunity for you
Investor sentiment suggests these four-star investments still seem to be on their way to five-star greatness, but it pays to start your own research on these stocks on 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.

Sign up today for the completely free service and let us hear what you have to say about the great and almost great companies that interest you.