Break out the beans and a keg of Boston Beer (NYSE:SAM) -- it's a backyard investing barbecue!

There are many good reasons for researching investment opportunities in a certain geographic area. Today, it's the Athens of America -- Boston, Massachusetts -- with its harbor and hills, old money and new ideas.

If you happen to live in Mission Hill or Back Bay, you already have a few advantages when it comes to evaluating the local market, such as access to local news sources and the word on the street, and a high probability of being a customer or employee of these companies. And if you're not a local resident, you might still want to know whether the weather matches the business climate -- a hot area could be chock-full of undiscovered treasures on their way to greatness.

Without further ado, here are the largest companies headquartered between Malden and Milton:

Company

Market Cap (billions)

CAPS Rating

Bull Ratio

State Street (NYSE:STT)

$22.9

****

95%

American Tower (NYSE:AMT)

$17.0

***

90%

Genzyme (NASDAQ:GENZ)

$16.8

****

93%

Biogen Idec (NASDAQ:BIIB)

$15.9

***

88%

Boston Properties (NYSE:BXP)

$13.1

*

69%

Data scraped from Motley Fool CAPS and current as of 5/18/2007.

That's as diverse a bunch as any -- a multinational bank, one cell phone tower operator, two biotechnology phenoms, and an office property REIT.

Apart from black sheep Boston Properties, these large-caps have earned the respect of our CAPS players -- and even the REIT looks like a strong contender in a sector down on its luck. Pitches for that stock oscillate between "market going down the drain" and "excellent portfolio of properties."

Genzyme sends hearts aflutter with talk of a possible takeover, another great portfolio and drug pipeline, and valuation low enough to please contestants on Deal or No Deal. Here's CAPS investor Firesale with a quick value take:

Forward PE of 16.51, the company's sales have grown by 16.5% for the 12-month period, has 'promising' products under development to treat genetic diseases, kidney disease and cancer among other conditions, and shares are down over 12% since January.

Look out below!
When you zoom out from the very top layer, you'll see a few patterns emerging. Medical sciences play a big part in the Boston economy, along with financial institutions and high-tech operations. The Rule Breakers team has drawn a bead on Beantown, picking data transporter Akamai Technologies (NASDAQ:AKAM) and three biotechs off its streets.

Beantown is awash in old money, prestige, and history. That's fertile soil for growing financial companies, and also for building one of the finest collections of research universities anywhere in the world. Over 100 institutes of higher learning are headlined by luminaries like Harvard, Tufts, and MIT, which in turn support the burgeoning biotech and high-tech industries.

The end result is like Austin scaled up to four million people, or Los Angeles after a pot of coffee and a cold shower. As long as the money and top-notch education systems remain, Boston will always be a primo business location.

Our CAPS players seem to agree. Out of the 37 companies in town that have earned a star rating, 19 carry at least four stars, versus only 12 grades of two stars or less. And our newsletter analysts thrive here, too -- there are seven active recommendations of our Motley Fool Stock Advisor, Motley Fool Rule Breakers, and Motley Fool Hidden Gems services in the City on the Hill.

Do you agree? Disagree? Feel free to weigh in on the Boston market -- or on any stocks at all, really -- by joining Motley Fool CAPS and blasting away with your ratings and commentary pitches. And if Beacon Hill isn't your 'hood, maybe we'll come around where you live the next time.

Further foibles:

Akamai is a Motley Fool Rule Breakers pick, and Biogen is a Motley Fool Stock Advisor recommendation.

Fool contributor Anders Bylund holds no position in any of the companies discussed here. He never veers to starboard because he doesn't sail at all; and he's never walked the gang plank and he's never owned a parrot, and he's never been to Boston in the fall. You can check out Anders' holdings if you like, or follow him around the world on these Foolish local-business treks. Foolish disclosure is a pirate who doesn't do anything.