BALTIMORE ( Stockpickr) -- The craze over social networking site Facebook has become palpable in the last several weeks. From the Golden Globe-winning film The Social Network to the site's estimated half-billion users, the attention being thrown in Facebook's direction shouldn't be overlooked by Main Street investors.

Founded just six years ago, the company's supposed $50 billion valuation is nothing to scoff at. Neither is the $450 million investment recently made by Goldman Sachs ( GS) on behalf of clients. That said, not all of the comments surrounding this company are positive.

There's been considerable talk of late about a potential bubble forming in the private equity world following Groupon's snubbing of a $6 billion offer from Wall Street darling Google ( GOOG) and now the massive valuation placed on Facebook in 2011. If suggested numbers are to be believed, the latest investment in Facebook puts the firm's valuation at four times that of Google and five times that of tech behemoth Apple ( AAPL).

Related: 3 Stocks That Could Rebound in 2011

There still may be ways for you to add exposure to this exciting trend to your portfolio. Here's a look at three ways to play the Facebook craze.

Bandwagon Plays

Don't put too much credence into the old saying that "it's a market of stocks, not a stock market." In fact, bandwagon plays really stand to rally on stronger sentiment for shares of Facebook.

Simply put, a bandwagon trade is a similarly positioned play that stands to benefit from its mere connection to a news-driven stock. As investors who can't get access to shares of Facebook (which is open only to wealthier, accredited investors) look for ways to leverage the industry's attractive attributes, they settle for buying shares of marginally related companies.

Among the best-positioned plays are News Corp. ( NWSA), whose once-dominant MySpace has undergone serious rebranding in an attempt to grow its market share, and Google itself, which offers a number of fragmented social media offerings.

Neither of these is a direct way to play the social networking business. News Corp.'s digital media offerings, which include MySpace and iLike, have been poor financial performers of late and require a significant operational overhaul to stop being a liability. Even so, the trend could boost shares as long as Facebook-mania keeps going strong.

Major holders of News Corp. include Prince Al-Waleed and Seth Klarman's Baupost Group, whose portfolio has 15.1% exposure to the stock. Frank Byrt called News Corp. one of five media stocks to watch in 2011, and with a B- buy rating, it's one of TheStreet Ratings' Top-Rated Media Stocks.

While Google's social media attempts have been somewhat less integrated with each other, they are at least financially viable and more utilitarian -- two factors that help them stand head-and-shoulders above the competition. Gmail is one of the biggest feathers in Google's hat right now: With 200 million monthly users, this service is much stickier than other social media Web sites and has the potential to help drive droves of users to any new offerings from the company.

All of that said, with these already-public valuations tempered by toned-down market conditions, these plays offer less downside risk.

Private Equity Plays

While average retail investors may not be able to invest directly in a private equity fund, they still may be able to profit directly from the industry by buying shares of a PE firm itself.

Take KKR ( KKR), for example. This $3.2 billion private equity firm went public in 2007, letting investors buy an equity stake in the NYSE-listed stock for the first time. While KKR focuses on leveraged buyouts and PIPE investment (private investment in public equity), the stock's cachet will likely help to spur shareholder interest if a private equity feeding frenzy takes place.

KKR shows up in Daniel Loeb's Third Point portfolio, and it was one of four asset manager stock picks for 2011 from Keefe Bruyette & Woods.

Of course, you could just invest in Google if you're interested in exposure to the private equity market. The company's venture capital arm, Google Ventures, is an early-stage investor in a number of private, technology-related firms, including several social networking sites.

George Soros is a Google bull, having increased his position in the stock by 1,541.6% in the most recent quarter. The stock showed up in a recent portfolio of stocks with large insider selling. TheStreet Ratings rates it a B buy.

Investment Banks

Increased interest in social networking firms could help fuel growth in an unexpected group of stocks: the investment banks.

That's because as the private equity market expands, venture capitalists begin looking for ways to exit their investments and add liquidity back into their funds. There are only two ways that PE funds can stage an exit: either through an acquisition of their portfolio companies by a larger firm, or though an initial public offering.

Because IPOs are far more lucrative for PE investors, and since the current IPO market has been warming up for the last 18 months, it's likely that we can expect a bevy of new firms to go public in the next couple of years. (Remember, the IPO cycle is a long, arduous one -- today's IPO filing may not bear fruit for years.) In fact, it's now expected that Facebook could plan its own IPO by 2012.

Although the private company owners are going to be big beneficiaries of their portfolio firms going public, so too are investment banks, who collect massive underwriting fees for their assistance in going public.

Underwriting fees took hard hits during the recession as IPOs were scarce, and bulge bracket firms such as Goldman Sachs and Bank of America ( BAC) have seen their underwriting revenues fall catastrophically. If that changes, expect beefier earnings from Wall Street's least popular clique.

Part of the reason for that is the blood-letting that went on during 2008. With fewer competitors, firms such as Goldman (which doesn't have the retail banking distractions of most other firms today) should see shareholders rewarded.

Goldman comprises 7.7% of Bruce Berkowitz's Fairholme Capital Management portfolio and 1.8% of Blue Ridge Capital's portfolio. According to Dan Freed, it's one of 11 inflation-proof financial stocks, and TheStreet Ratings rates it a B- buy.

To see these stocks in action, check out the Facebook Frenzy 2011 portfolio on Stockpickr.

-- Written by Jonas Elmerraji in Baltimore.

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At the time of publication, author had no positions in stocks mentioned.

Jonas Elmerraji is the editor and portfolio manager of the Rhino Stock Report, a free investment advisory that returned 15% in 2008. He is a contributor to numerous financial outlets, including Forbes and Investopedia, and has been featured in Investor's Business Daily, in Consumer's Digest and on MSNBC.com.