December is a big month for charitable donations. Many nonprofit organizations receive the lion's share of their annual contributions between Thanksgiving and New Year's Day, according to philanthropy expert Charity Navigator.

Though the economy is still wobbly, many people feel it's important to give. More than seven out of 10 say they expect to donate the same or more in 2011 as they did last year, according to a recent American Red Cross poll.

After 17 years running a successful travel and event management company in Cherry Hill, N.J., Linda Davis did what many entrepreneurs dream about: She retired to Naples, Fla. "I thought I would be happy relaxing on the beach and reading," she says. "That lasted about three months."

Davis, 59, says she missed learning new things and meeting new people. "I felt like I needed to do something more with my life," she says.

Civic Ventures announced winners of the 2011 Purpose Prizes today, awarding $100,000 each to five social entrepreneurs over 60 who founded projects to aid orphans, refugees, impoverished families, the unemployed and the environment.

"This year's Purpose Prize winners saw systemic problems -- like institutional care for orphans and global warming -- and used their experience to come up with big, systemic solutions," says Alexandra Céspedes Kent, who directs the Purpose Prize program. "Like so many other encore entrepreneurs, they want first and foremost to make a difference."

Most areas of the country striving to become innovative centers of the 21st century economy seem to think the answer is to attract the most talented college grads and brash twentysomething entrepreneurs. So it's kind of a pleasant surprise that my old hometown of Pittsburgh is taking precisely the opposite approach.

The city is offering a $100,000 prize to "experienced dreamers" age 45 and over who are willing to relocate to the former smokestack-city-turned-high-tech-mecca and take a stab at achieving their second-act ambitions.

Okay, say you like to help people out, maybe with your time and money. Usually, we do that by finding an effective, trustworthy nonprofit organization.

Problem is that there's more than a million of 'em in the U.S., and the news has alerted us that many don't get anything done, and some are outright scams.

Gracie Cavnar was appalled when she learned that elementary schoolchildren in Texas had access to vending machine junk food. "I thought that marketing junk food to children when they were outside their parents' control was morally wrong," says Cavnar, 59. "In this process, I discovered the looming epidemic of childhood obesity."

It was 1998, and the first studies on childhood obesity were being published. Cavnar had just retired from careers in architecture, hospitality and marketing to write -- and she'd found a subject. Eventually, she wanted to do more than write about childhood obesity for newspapers and magazines, and in 2005 she founded the Recipe for Success Foundation, a nonprofit nutrition education program for school-age children. Because of Cavnar's success in the Houston area, the Obama administration has asked her to take her program to the national level.

Launching the Program

Psychiatrist Judith Broder, founder of The Soldiers Project, is one of 13 Americans who will receive the Presidential Citizens Medal at the White House on Thursday.

SecondAct profiled Broder last year and detailed her organization's efforts to provide free counseling to returning veterans and their families. To date, 700 volunteer therapists have provided more than 10,000 hours of confidential psychological services to more than 300 military families. The organization has expanded far beyond Broder's Studio City, Calif., home, now helping soldiers in Chicago, Boston and New York.

While some industries continue to cut jobs, nonprofits are adding them. That makes it a good time to investigate openings at charitable organizations.

From 2009 to 2010, jobs at U.S. nonprofits grew 8.8 percent, according to an annual report from the Agency for Healthcare Research and Quality, which tallies employment at for-profit businesses and nonprofit organizations to collect information on health insurance coverage. When it comes to jobs, the biggest nonprofits fared best, with organizations of 1,000 or more workers showing a 16.7 percent increase in employment in 2010, compared to a drop of 3.8 percent for groups with a staff of fewer than 10, according to the report.

Many U.S. nonprofits are cautiously optimistic about hiring and believe the worst of the economy has passed, according to a new survey from Idealist.org, the nonprofit jobs site.

Of 3,000 organizations polled, 49 percent said they would keep current staff levels this year, 42 percent said they were hiring for new positions, and only 9 percent planned to reduce staff. "We made it through the hardest period, and we're still here," one survey participant wrote. "We will fill positions that become vacant and hire grant/specially funded employees," another wrote.

I remember exactly where where I was just before 9 a.m. on the morning of September 11, 2001. Chances are you can, too. We'll never forget those terrifying moments of horror and confusion as long as we live, and we'll always mourn those lost. But as President Obama reminded us in this recent radio address, 9/11 also was a time when Americans responded as Americans do in times of crisis, and came together to help one another get through the trauma and to climb back to our feet. Now, he urges us, it's time to do it again, by joining a national day of service in our own communities.

The national day of service actually is an idea conceived in the wake of the tragedy by families of September 11 victims who created an organization, My Good Deed, Inc., to encourage other Americans to follow their example. Since then, the movement has picked up momentum, and in April 2009, the president signed legislation making the day of service an official national event. Here's a video, entitled "I Will," in which some volunteers -- including both ordinary folks and celebrities -- talk about what they'll be doing on Sunday.

• Go to the 911day web page and type in your location to come up with a list of Sunday projects within a 25-mile radius of your home. It's possible to further narrow down potential choices according to the type of community activism that most appeals to you, whether it's teaching someone to read, feeding homeless people or working on an environmental cleanup project.

• Find information about service projects by visiting Serve.gov or My Good Deed's partner organization, the HandsOn Network.

• Follow #911day on Twitter for the latest news and volunteer efforts projects.

• The Huffington Post compiled this selection of planned 9-11 projects across the nation.