These three companies just didn't live up to Mr. Market's expectations last week. Sometimes an earnings stumble is a signal to sell, but digging in the dirt is also a good way to find turnaround candidates while they're getting beaten down.

Lost on Wall Street
Let's kick things off with navigation tools expert Garmin (Nasdaq: GRMN). The gadget guru reported earnings of $0.67 per share on $664 million in revenue, but the average analyst wanted $0.75 per share and $714 million, respectively. And so the share price fell nearly 12% that day. The miss was clearly North American in nature, as that was the only geographic region where year-over-year sales growth (at 27%) trailed the total revenue growth rate of 35%. European sales climbed 43%, and Asian revenue clocked in at double the year-ago figure. It's just too bad that 62% of Garmin's sales stay within North America.

On the other hand, that particular excuse might not hold water in the GPS technology space. Rival NAVTEQ (NYSE: NVT), now in the midst of being acquired by cell phone giant Nokia (NYSE: NOK), just reported 40% overall sales growth with a 54% American boost -- that includes South and Central America in the reportable region.

All in all, Garmin's management is pretty happy with the quarter, as most companies would be after reporting 35% top-line growth and steady profits. The company is clearly too healthy to labor under a miserly 10.8 P/E ratio, and should climb back to a more respectable high teens or lower 20s once Mr. Market gets his head screwed on straight again. If only there were a positioning system for him.

Eh, what's up, Doc?
Our second disappointment today comes from media maven Time Warner (NYSE: TWX). The company reported earnings of $0.21 per share on $11.4 billion in revenue, but the Wall Street consensus called for $0.23 in EPS and $11.4 billion in sales. That's one target missed.

Warner is in the middle of large-scale restructuring. When all is said and done, AOL will be split into two reportable segments -- one for Internet access lines, the other for the online content portal -- and possibly sold off piecemeal. Time Warner Cable (NYSE: TWC) has a ticker of its own today, but is still just a division within Time Warner; that's about to change, as management just told us that "a complete structural separation" of the cable unit is the best choice for all shareholders.

So the Time Warner of tomorrow should be leaner, meaner, and more focused on its core competencies -- producing and distributing forms of entertainment and information media. The cable TV franchise will be doing its own thing, and AOL will perhaps fit in better with Microsoft (Nasdaq: MSFT) or Yahoo!. All of this sounds right as rain, but it'd be silly to invest in a company that's changing this much, this fast, without a clearer idea of the final plans. Check back in a few months.

Black gold?
If you think Time Warner's $11 billion in sales is impressive, wait 'til you see our next underperformer. Oil titan Exxon Mobil (NYSE: XOM) disappointed analysts with a mere $10.9 billion -- in net profits. Wish I had problems like that.

Then again, maybe not. Wall Street had expected earnings of $2.14 per share, but Exxon only managed $2.03 per share. If I came up roughly $500 million short on any financial target, as Exxon just did, there would be consequences and repercussions. In the case of Exxon, the market simply shaved about 3.6% off the world's fattest market cap, destroying more than $17 billion of potential investor value.

While other companies might suffer from too much American exposure, I bet Exxon wishes it could enjoy the comparative political stability here, instead of seeing its production stymied by the whims of leaders in Russia, Nigeria, and Venezuela.

As my Floridian fellow Fool and neighbor, David Lee Smith, points out in his earnings breakdown, you almost have to believe that oil prices are headed for a correction. I'd give Exxon about the same grade as Time Warner: Check back in a few months.

Some of these underperformers are victims of larger circumstances; others might have only themselves to blame. It's up to you to decide which down-on-their-luck companies should be able to pull themselves up by the bootstraps, and which ones are stuck in the mud for real.

Further Foolish reading:

Seeking great deals on unfairly punished stocks? Philip Durell and his merry band of Fools at the Motley Fool Inside Value newsletter service are standing by to help you find great stocks at ridiculously low markdowns. Microsoft is an Inside Value recommendation. Sign up for a 30-day trial subscription to see whether bargain hunting is right for you. Garmin, Navteq, and Time Warner are Stock Advisor picks. Garmin is also a Global Gains selection.

Fool contributor Anders Bylund holds no position in the companies discussed this week, and a navigation system would be wasted on a guy who drives 50 miles a week, tops. The Fool has an ironclad disclosure policy, and you can see his current holdings for yourself.