Even if you're still happy at your job once you've paid off the house and mailed in your kids' final college tuition bill, career counselors advise taking a formal career assessment test as you approach—and decide how to spend—those years formerly known as retirement.

These tests, available online or through community college career centers, job placement offices, or private career coaches, can help you understand how your skills, passions, and preferences have evolved over the years. If you can pass your days doing things you care about, "then working longer won't feel so tedious," says Laura Carstensen, director of the Stanford Center on Longevity.

To jump-start the brainstorming about what sort of work you'd find fulfilling into your 70s, you can find a list of online personality and career tests at www.jobhuntersbible.com. TheCareer Key at $9.95, for example, ranks you on six personality dimensions (artistic, investigative, enterprising, social, realistic, and conventional) and matches you with jobs you're likely to enjoy.

Someone who is highly investigative and enterprising, say, might be guided to explore urban planning, sales engineering, or scientific reporting. Other options: the free Career Values Testand the Career Interest Profiler, which costs $14.95.