Baron Nathan Mayer de Rothschild told us all to "Buy when there's blood in the streets!" That maxim makes tons of sense today for individual investors -- but it applies just as well to mergers and acquisitions.

I thought that proverb was about investing!
Sure, corporations can follow the same rules as the rest of us Plumber Joes and Preschool Teacher Jills. The dictionary defines a corporation as "a body formed and authorized by law to act as a single person," so it's not completely wrong to ascribe human needs and emotions to businesses.

So when the market takes a 35% haircut in one year, and 23% in one tiny month, you're drooling over all that delicious sanguine sauce flowing between Broadway and South Street. Strong companies with deep pockets are doing the same, because growth by acquisition is still growth, and they see some of the best buyout opportunities in decades.

Let's have a look at some of the Wall Street hunters and their prey.

The usual suspects
Microsoft (NASDAQ:MSFT) never really gave up on its pursuit of Yahoo! (NASDAQ:YHOO). The online portal could boast an enterprise value of more than $35 billion a year ago, but that juicy corporate price tag has dwindled to just around $14 billion today. Mr. Softy was once willing to pay as much as $47.5 billion for a serious foothold in the e-commerce district. With Yahoo!'s future looking dimmer every day, maybe Steve Ballmer is waiting for the price to drop even further. But don't be surprised if he jumps out with a much smaller bid sometime soon, if only to spite Google (NASDAQ:GOOG) while he can. Steve will look generous, even with a lowball offer.

Virtualization expert VMware (NYSE:VMW) has also seen its market cap evaporate; its stock price has declined more than 80% in the past year. At roughly $8 billion, its current market cap seems like a very affordable morsel for one of the software giants. But Microsoft probably wouldn't get past antitrust concerns, any more than Google could buy Yahoo! outright. Many of the other true titans of the industry face the same obstacle. Storage specialist EMC (NYSE:EMC) still owns approximately 84% of VMware, and it would probably be happy to buy back the rest of the shares at an attractive discount. There'd be another IPO in a few years, when the market gets over today's panicked state.

Gimme some news, you big tease!
How about a retail veteran with high-tech ambition and proven leadership? Video rental maven Blockbuster (NYSE:BBI) has cratered, tumbling 76% in 12 months, despite 7-Eleven veteran Jim Keyes visibly righting the sinking ship. The resulting $1.1 billion enterprise value should be easy for any interested acquirer to digest.

The company's own Circuit City buyout plans have been likely shelved, because the target was in worse shape than Blockbuster itself ever was. Without the extra baggage, Blockbuster is more of a target than a loaded gun. Its triple-play business model in online, by-mail, and in-store movie rentals could convince a major Hollywood player like NBC Universal or Walt Disney (NYSE:DIS) to snap Blockbuster up. The buyer would get instant access to a nationwide distribution system in three parts, plus a quality management team for the new division, all at a very reasonable price.

And then what?
Baron de Rothschild would be thrilled to work in mergers and acquisitions today, as the blood runs thick and syrupy down Wall Street's gutters. Fire up your favorite stock screener, look for worse-than-average share price cuts and an affordable valuation, and start separating the true losers from the beaten-down but brilliant businesses that deserve to be part of something bigger. There are tons of attractive buyout opportunities in a market like this.

Microsoft is a Motley Fool Inside Value recommendation. VMware and Google are Motley Fool Rule Breakers picks. Walt Disney is a Motley Fool Stock Advisor recommendation. Try any of our Foolish newsletter services free for 30 days.

Fool contributor Anders Bylund owns shares in Disney and Google, but he holds no other position in any of the companies discussed here. You can check out Anders' holdings or a concise bio if you like. The Motley Fool is investors writing for investors.