Marjorie Baer used to joke about her retirement plans. She wasn't married and had no kids, but she didn't intend to be alone―she and all her single friends would move into a fictional home she called Casa de Biddies. Instead, Baer developed terminal brain cancer when she was 52. But just as she'd hoped, her friends and family provided her with love and care to the end.

Baer's friends Lee Ballance and Mary Selkirk were walking their dog one afternoon in July 2006 when they saw an ambulance in front of her house. Baer had had a seizure and collapsed. Ballance, a physician, hopped in his car and followed the ambulance to the hospital to be at Baer's side while doctors tried to figure out what was going on. When they did, the news wasn't good: She had glioblastoma multiforme, a particularly aggressive form of brain cancer.

Ballance was only the first of Baer's friends who became her unofficial caregivers. Until her brother Phil Baer put his marriage and work in Los Angeles on hold to care for his sister during her final weeks, they cobbled together a system to watch over their friend and allow her to keep some of the privacy and independence she cherished.

Baer's good friend Ruth Henrich took the lead. That seemed natural: Henrich, then 58, and Baer both worked in publishing and lived in the same duplex. Though busy in her job as an associate managing editor at salon.com, Henrich took Baer to doctors' appointments and helped her deal with all the aspects of life that were becoming increasingly mysterious to her―answering machines, TV controls, and even phone numbers. After Henrich sent out an e-mail request, a group of volunteers signed up to ferry Baer back and forth to radiation therapy. Others in Baer's circle offered up particular talents: A nurse friend helped Baer figure out how to get what she was due from Social Security and her disability insurance; an attorney pal helped Baer with her will; a buddy who was an accountant took over her bills when she could no longer manage them. "There was this odd sense that the right person always showed up," says Ballance.

Not that it was easy. "I had to know at all times who was going to be there and anticipate what Marjorie would need next, so it was always on my mind," says Henrich. "It was something I wanted to do, but it also never went away." Still, their jury-rigged arrangement worked remarkably well. Even as Baer lost the ability to read and write and engage in conversation over the course of the year, she was able to continue to live on her own, walk to the market, take the subway to painting classes, and even fly to Iowa by herself to visit her brother Tom and his family.

"She was a generous person," says another friend, Elizabeth Whipple, "and it came back to her in truckloads."

Unmarried women are one of the fastest-growing demographic groups in America, and increasing numbers of men are remaining single, too; experts are concerned about how caregiving will be managed for both groups as they age. If the experience of Baer's friends is a guide, the Internet will play a role. It's already making it possible to create communities of caregivers who may have only one thing in common: the person who needs their help. On personal "care pages" set up through services such as Lotsa Helping Hands, friends and family members can post a list of tasks that need to be done, volunteer to do them, and keep updated on the person's condition. As Baer's cancer progressed, for example, her friends set up a page on Yahoo! where people could sign up to deliver meals or do errands.

Eventually, their help wasn't enough. One morning, a year after Baer's diagnosis, Henrich checked in before work and found Baer on the floor. Though she wore a panic button on a chain around her neck, she hadn't used it. "I don't know how long she had been there," Henrich says.

That was when Baer's brother Phil stepped in. He and Tom had taken turns earlier making trips to Berkeley to care for their sister; now Phil, who lived in Los Angeles, took leave from his job as head of air-conditioning and heating at CBS Studio Center―and from his understanding wife, Joyce―to care for Baer full-time. "There was just no question in my mind that I would do anything I could, including switch places with Marjorie," he says. "It made me realize how much I loved her."

For the next few weeks, Phil looked after her during the day. He oversaw the nighttime caregivers and consulted with the hospice workers who assisted with medical issues and helped him prepare for Baer's death. But even then, his sister's loyal friends were irreplaceable, he says, providing both practical and emotional sustenance.

Several of Baer's friends were there when she died. "We were all trying to help ease her passing," says Whipple. "Phil put his hands on her chest, and she let go."

Catherine Fox, one of the friends who was present when Baer died, was deeply affected. "It was so comforting to know that if you're willing to ask for help, the generosity of family and friends can be phenomenal. It makes me feel secure and hopeful to know that help is there when you need it."