In a way, Alexander Graham Bell was the Mark Zuckerberg of his era.  The telephone would quickly transform the world – and become the first “viral” technology.

In fact, it would become the basis of what eventually would be the world’s biggest company:  AT&T (NYSE:T).  Until it was broken up by the federal government in 1984, it was a monopoly and as a result, extremely profitable.

Now it looks like Facebook could also turn into a communications monopoly – but this time, it will incorporate most of the world.  So far, there are about 700 million users, and many of them start their day on the site.

No doubt, Facebook is causing panic for dot-com incumbents like Google (Nasdaq:GOOG), Yahoo (Nasdaq:YHOO), Amazon.com (Nasdaq:AMZN) and Microsoft (Nasdaq:MSFT).  None of these companies can find a way to get traction with social networking.  Google’s executive chairman, Eric Schmidt, even recently said he “screwed up” this megatrend.

The true power of Facebook is that it has become the digital footprint for people’s interests and trusted relationships – which is the “holy grail” for marketers.  Facebook would have to be extremely stupid to not know how to monetize this.

And with its credit system, the website will be able to create its own currency.  What company can claim this?

Already, Facebook has a value of $85 billion (according to the recent trades on marketplaces like SharesPost).  Keep in mind that the company received an investment from Goldman Sachs (NYSE:GS) in February at a $50 billion valuation.

But in light of the growth opportunities – which will scale across the globe – those figures looks cheap.  I believe Facebook will ultimately becom the most valuable company.

Reaching $30 billion to $40 billion in revenue in the next five years doesn’t seem like a stretch.  And the revenues are likely to command substantial margins (especially from the credits business).  Unlike Groupon, Facebook does not have to spend huge amounts to get is users.

Assuming the company goes public next year, it also will have the heft to pull off major acquisitions.  Perhaps the company will purchase other social operators like Zynga or Twitter.

But could anything derail Facebook?  The biggest risk factor is the one that all emerging monopolies must eventually deal with:  the federal government.  But if history is any indication, such an action will likely take some time.  In the meantime, Facebook will be the no-brainer stock for growth investors.

Tom Taulli’s latest book is “All About Short Selling” and he has an upcoming book called “All About Commodities.”  You can find him at Twitter account @ttaulli.  He does not own a position in any of the stocks named here.