[By Doug Most / Boston Globe Magazine]

Now where is that waiter?

It's the parental quagmire. Date night is supposed to be relaxing. The kids are asleep. The mayhem of the week is gone. And yet it's impossible to relax completely knowing a baby sitter is back at the house, watching television on your couch while eating your cookies and texting her friends - for $12 an hour.

Tick, Tick, Tick.

It's 9 p.m. If the check comes in five minutes, the thought process goes, and we're done by 9:15, we can be home by 10 p.m. and not let another $12-hour begin. That would be $50 for baby-sitting plus the $80 dinner tab, plus $20 for the movie, for a $150 evening.

This tiramisu is delicious. Now where is that waiter?

At a time when everyone's looking to trim nonessential expenses, baby-sitting is a logical place to cut. Sure, it's nice to get out occasionally, but it's expensive and times are tight.

But there is a way to have baby-sitting and a cheap night out. It just requires a little effort, ingenuity, and community spirit. If you spend $100 a month on baby-sitting, you could save $1,200 a year.

A baby-sitting co-op with friends and neighbors - whether it's to help a parent run a few errands child-free, or get both parents an adult night out on the town - is a way to take advantage of your circle of friends with children so that everyone can benefit.

It can be a formal co-op, with a website and a secretary who tracks the favors, or informal, with a list of phone numbers or e-mail addresses and nothing more.

Or it can be a simple arrangement between two couples. My wife and I have often gone to the house of some good friends to watch their children one night, and in return one of them came to our house the next night while our children slept. Both couples got date nights with no baby-sitting costs and the comfort of knowing that parents we trust were watching our kids.

Christine Andacic, a mother of two in Billerica who organizes a local parents' group called My Moms' Group Baby-sitting Coop through www.meetup.com, said she has 82 members, from Billerica to Burlington to Chelmsford. New members start out with 20 points, she said - for each favor they perform, they get points, and for each favor they request, they subtract points.

If a mom drops off her two children at another member's house for two hours, she loses four points, one for each child and one for each hour. So her 20 points would drop to 16, while the parent who watched those children would gain four points and go up to 24.

There are specific rules about the point system. Watching children at night costs extra points because it takes parents away from their own families. And no negative balances are allowed. A family that drops below zero cannot ask for any favors until they have performed favors to get back above zero.

An organizer in the group posts a spreadsheet on the website to track everyone's points.

"It's probably used once a week now," Andacic said. "Everybody is just starting to get know each other."

The idea of baby-sitting swaps is hardly new, according to author Carole Terwilliger Meyers, who wrote a 1976 book (now out of print) called "How to Organize a Baby-sitting Cooperative and Get Some Free Time Away From the Kids," in which she claimed the concept was born during World War II, when women left behind to keep up their homes and raise children relied on each other.

"A lot of people start the co-ops not to save money, but also to assure their babies are being taken care of by other parents, who have that instinct on how to deal with children," said Meyers, 63, a mother of two adult children who lives in San Francisco. "I know I had that feeling, rather than leave my baby with a teenager who doesn't have the same instincts."

Creative baby-sitting solutions are especially vital in tough economic times. With everybody looking for ways to save, a night on the town away from the children could be seen as a luxury. But Crista Martinez Padua, executive director of Families First Parenting Programs in Cambridge, said that would be a mistake.

"Parents are more than likely working harder than ever now, and children see that stress," she said. "Children are better emotionally when they see their parents taking care of themselves emotionally."

She said the parents coming to Families First these days talk about feeling guilty about working hard and being away from their children. They describe scenes where their children come home from school and say a friend's father or mother just got laid off and they wonder if that could happen to their parents.

"You have to allow yourselves some small pleasures," she said. "It does replenish your spirit. Date night doesn't have to be extravagant. Just a walk down the street hand in hand doesn't have to cost a penny, but it's a moment to catch their breath and check in with each other."