For a few years, Christine Marchuska was living the high life. After graduating from Cornell University in 2002, she worked as a day trader and eventually landed a plum job at a major investment bank. But last winter she, like many Americans, began to feel the economic squeeze. "I had learned from my time as a trader that one day you could be up and the next day you could lose everything," says Marchuska. She was right to worry; she was laid off in May. She wasn't the only one. Since January, more than 1.9 million Americans have lost their jobs. About 533,000 of those jobs were lost in November alone, according to Friday's Bureau of Labor Statistics report. Last month's losses amounted to the largest single month drop since December 1974.

But rather than linger among the ranks of the growing unemployed, Marchuska has found a way to turn her layoff into lemonade. When her pink slip finally arrived in May, she lumped her savings together with her severance pay and some seed capital from her brother—altogether about $40,000. With that, she took a flurry of classes, networked with anyone who would speak with her, and ultimately launched her dream business, Marchuska, a line of sustainable clothing that donates 5 percent of its profits to charitable causes. Despite the broader economic downturn, the fledgling company, based in Endicott, N.Y., has gained the attention of a few Manhattan boutiques and may rack up $100,000 in sales this year. And according to Marchuska, there's one invaluable benefit: "I'm not at the mercy of some corporation that can get rid of my job at any time."

Layoffs often provide an opportunity to undergo an extreme career makeover, giving you the chance to pursue options you might never have considered when your former job was a given. Of course, not everyone has a big stash of cash or monied relatives to get them through. However, even if you don't have a fat bank account, you can still make a career transition, says Robin Ryan, a career counselor in Seattle and author of "60 Seconds and You're Hired!" (Penguin). The severance and unemployment insurance payments that often come with a layoff can give you time to re-examine your career path, she says. Plus, she adds, "The biggest salary increases typically come from moving from one job to another when you negotiate effectively."

So how can you profit from a layoff? Some companies offer job retraining and career counseling as part of their severance packages, so be sure to ask the company's human resources department about any such options, Ryan says. Community colleges, alma maters and professional associations also have low- or no-cost career transition resources, as well as networks of alumni and members who may be able to help. Information about federally and state funded workforce development and training programs is available at your local or state labor department, local unemployment office and community college workforce development department, Ryan advises. These may include classes or on-the-job training programs that are available at little to no cost, especially in geographic areas or industries that have been hard-hit by job losses. In Marchuska's case, she paid for her classes out of her own pocket, but made contacts that helped her find out about other classes and contacts that have helped her business.

You can also use the skills that you have from your current job to transition into doing something similar in a new field, says New York City career consultant Jeri Sedlar. That's what Tabitha Frizzell Hanes did. Blindsided by unexpected job loss after she returned from a long weekend with her long-distance boyfriend in his hometown of Richmond, Va., she took a few weeks to get her affairs in order, packed up her dog and headed back there. While searching for pet-friendly apartments, she found an opening with the local branch of the Society for the Prevention of Cruelty to Animals. Once she got her foot in the door with an entry-level gig, she eventually became the shelter's first community relations manager.

To make up the initial income difference, she took a second job as a waitress. But that was fine with her. "I was so fulfilled working with animals, really doing what I loved to do. It was hard, but it was worthwhile to feel like I was making a difference," she says. With her promotion came more pay and she was able to give up her second job. Before making a big transition, Ryan says that you need to ensure that you're moving into a field that offers a future. "Ask yourself, is this a job that will be in demand in five years? Is it a growth industry? What kind of training do I need to pursue this career?" she says.

Once you've decided to go for it, both she and Sedlar say that networking is essential. Ryan adds that about two-thirds of all jobs are found through networking. "Get out and meet people. Talk to your friends and former co-workers and bosses, colleagues and neighbors," she says. "Anyone who can help you make connections."

Landing an internship or part-time job in your target field are good ways to gauge if you'll really like the job, says Sedlar. For those with more discretionary income, companies like Vocation Vacations let you test-drive a variety of coveted occupations—chef, event planner, bed and breakfast innkeeper, actor, etc.—for a week or so by arranging experiential working vacations in your chosen field. That way, she says, you don't sink time and money into a transition that turns out to be worse than where you started.