In the boom times before the recession began in December 2007, when consumers felt flush, it wasn't enough to have one home, they also bought vacation property. It wasn't enough to build one new condo building, developers had to construct five within a 10-block radius. Credit was flowing and people allowed their cup to overflow. Then the recession hit, ravaging the real estate, retail, construction and manufacturing sectors. Although economists declared the end of the downturn in the fourth quarter of 2009, the U.S. jobless rate hit a high of 10.2 percent during that period, the first time in 26 years that it was in the double digits, according to the Bureau of Labor Statistics.

High unemployment and changing consumer buying habits have led to some dramatic changes in the makeup of the Inc. 5000. The construction industry, which listed 354 companies in 2009, experienced the largest drop (40.7 percent) this year of all 25 categories. The next two to plummet were human resources and manufacturing, both with about a 37 percent drop, reflecting joblessness and the reduced production and lower spending that comes with it.

Yet, it wasn't all bad. Though they do not constitute an industry per se, companies that help consumers unwind their previous bad choices make up a new cohort on this year's list. Debt consolidators such as Reliance (No. 452), Nelson Gamble & Associates (No. 999), and Accelerated Financial Solutions (No. 1,874) have all made significant strides in revenue growth.

The top-ranked among these companies is first-time honoree Debt Free Associates (No. 7.) The Oklahoma City company has experienced 12,376 percent growth since 2006. The company helps its clients get their debt payments under control; among other groups, the company serves quite a few entrepreneurs who launched businesses, fell short of their goals, and had put their personal assets at risk. "A lot more of our customers now are not exactly prime borrowers, but not subprime, either," explains CEO Brad Smith. With the rise in creditworthiness of the company's average customer, the average debt load they bring in has increased as well—from about $27,000 per debtor in 2005 to more than $46,000 this year.

At the same time that there are more debtors looking to consolidate more debt, there is also less competition, which has further fueled Debt Free's growth. "Years ago," Smith explains, "I would have said our biggest competitors were the companies that provide debt consolidation through a home-equity loan or a line of credit. With the state of the real estate market, those companies are practically nonexistent at this point."

Likewise, those offering a way out of timeshares, such as Timeshare Relief (No. 1,288), are becoming popular. Back in 1999, David MacMillan and his wife Cindy realized that investing in a Las Vegas timeshare had been a mistake. With four kids and six competing schedules, the couple couldn't find time to get away. They tried putting the timeshare up for sale, but after shopping it around to several timeshare listing and resale companies, they found there was no way out of their contract. A timeshare, they soon learned, is a lifetime commitment that can cost an average of $646 a year in maintenance fees. And though it's often billed as an asset, the MacMillans realized that, when a timeshare goes unused, it is actually a liability.

After performing extensive research on the subject, and finding out they weren't alone in their unsuccessful quest to escape the contract, the couple founded Timeshare Relief in 2004 in Torrance, California. For a fee, the company will help unhappy timeshare owners get  out of their contracts. Timeshare Relief then pays one of its five partner brokerage companies to take on the abandoned timeshare.

Though the MacMillans were their own first customers, the company has seen the majority of its growth in the past two years, as more timeshare owners have found themselves suddenly unemployed and eager to reduce maintenance costs or recoup part of their investment or both. So far, Timeshare Relief has helped more than 50,000 people around the country get out of their contracts.

"There's a lot of people in pain out there who see their life savings being wiped out, who we can help," says David MacMillan. "We're fortunate to have an industry that's actually done well in this economy."

SecondMarket (No. 270) is an example of how periods of crisis can lead to innovation. An eBay-like site for illiquid assets—such as asset-backed securities, bankruptcy claims, collateralized debt obligations, private company stock, and residential and commercial mortgage-backed securities—SecondMarket serves buyers and sellers through an online marketplace that is both centralized and transparent—unlike the traditional means of access to such types of investment activity. "There's been a tremendous amount of trust destroyed throughout our financial system. People think Wall Street is fixed, and the public markets are like casinos," says Barry Silbert, founder and CEO of the auction site. "The big financial institutions make so much money off the spread and the opacity [of the trading of these types of assets], they are essentially taking money out of the hands of the buyers and sellers. There needed to be a way to connect buyers and sellers directly and not be beholden to the large financial institutions and the way they do things."

Silbert attributes SecondMarket's 1,155.64 percent growth since 2006 to the attractiveness of the platform's transparency and centrality, as well as to the service it provides to those involved in the liquidation of private company shares (employees, investors, and the companies themselves). "A shareholder can exit a company through an IPO, merger or acquisition. The problem is, the time it takes to go public has increased from four or five years a decade ago to more than 10 years. Today, less than 20 percent of companies do an IPO of $50 million or less, while 10 years ago, it was 80 percent. The public markets have become much more of an exit, an alternative, for really big, seasoned companies."

Silbert calls his company's market for private company stock a "spring training" period: an alternative market structure for years five through 10 before an IPO. The company can decide who's buying, who's selling, and what information is shared. "Instead of forcing the company to fit into what a market expects of it, we're turning it around and allowing a market to form around what a company wants." And employees have an alternative to growing old along with their options.

Similarly, the resale of retail items is growing in popularity because many companies are now offering options that were unavailable before. For example, consumers have more and more ways to turn in their unwanted cell phones and other gadgets and be rewarded in cash—not to mention the satisfaction of not contributing to further e-waste. Gazelle (No. 24) collects unwanted electronics such as cell phones, game systems, and mp3 players for resale, charity, or responsible recycling. CEO Israel Ganot proudly reports that the company has just awarded a refund to its 100,000th customer. And with the average refund running at about $100, it's not a bad way to get some quick cash.

Used and vintage clothing stores are also blossoming all over the country as more and more shoppers embrace them for being both sustainable and economical. Buffalo Exchange (No. 3,850) was a pioneer in the industry, opening its first store in 1974 in Tucson, and it keeps growing every year. Last year, it opened new stores in Minneapolis, Boston, New York, and Ventura, California, for a current count of 37 stores and two franchised locations in 14 states. "We do well in good times, and better in bad times," notes CEO Kerstin Block. The business experienced modest (2 percent to 3 percent) same-store growth last year, but the major difference last year, Kerstin notes, was that "many more people wanted to sell stuff." In addition to choosing from the designer wear, basics, vintage, jeans, and leather goods for sale (80 percent of which is used), customers can clean out their closets and get a decent percentage of the clothes' and accessories' resale value, in cash or in trade, on the spot. Buffalo Exchange just opened a new store in San Antonio and has two more slated to open this year—a second location in Boston, and a third location in New York.

The above companies are designed to thrive in hard times, but they also can remain strong during the upswing. Let's see where they rank on the list next year.