The Baby-Sitter’s Club may be long gone, but admit it, you miss the days when Kristy, Mary Anne, Claudia and Stacey organized all your babysitting ventures for you. Thankfully, SittingAround, a Boston-based startup, is taking a page out of those seventh-graders’ book and revolutionizing the way parents and babysitters connect, schedule and manage their sessions.

A 2011 MassChallenge alum, SittingAround debuted in June 2011 as an online babysitting co-op, a simple way for parents to swap their time for free childcare, and has since helped over 3,000 parents connect with other parents in six cities across the country, including Boston, New York, D.C., Philadelphia, Chicago and Seattle.

However, about 30 percent of those parents would use the co-op, but they didn’t necessarily want to participate in swap – I mean, who wants to watch someone else’s bratty children? These parents had to resort to finding a babysitter within their own, often limited, networks.

“What do you do to schedule a babysitter these days?” asks SittingAround co-founder Erica Zidel. “Craigslist? Call someone?” In our modern day of texting, social networks, Gmail and the like, Zidel realized there was no quick and easy way for parents to find a sitter. “Babysitting is a $5 billion per year industry, but it looks the same today as it did 50 years ago,” she explains.

Enter the Sitter Marketplace, a new tool launched by SittingAround last week that allows parents to connect with, vet, book and share paid babysitters. The entire marketplace relies on “passed trust,” which consists of background checks, recommendations and connections between sitters, parents, neighbors and friends.

Passing trust, explains Zidel, is “an innovative feature where we overlay the social graph on top of the marketplace. For example, a sitter many look normal and nice, but if your friend has actually used them for childcare before, you can see that and trust her recommendation.” The better the sitter, the more trust you gain.

“Sitters used to be at the mercy of one to two clients,” says Zidel of the old word-of-mouth system of passing along babysitters. However, within the new Sitter Marketplace, “Sitters can create their own calendar, and list their availability. It allows sitters to work as much or as little as they like, and run their service as a true business.”

With all the other online sites for babysitters like Sittercity and Care.com, Zidel says SittingAround’s Sitter Marketplace stands apart from the crowd because it relies heavily on trust. “That first generation of sites brought babysitters and parents online, but didn’t recreate the neighborly, trustworthy experience that the whole babysitting industry is very much dependent on,” she says.

Within the next six to 12 months, SittingAround hopes to add online payments to the transactions, so that the entire babysitting process – aside from the actual childcare, of course – can be completed in the online marketplace. Zidel also hopes to incorporate more ways for users to pass trust and build out their reputable networks using social tools. Eventually, Zidel wants to map this trust system onto other industries – but that’s still a long way down the road, she says.

In the meantime, SittingAround is focused on giving babysitting a “facelift.” For a $5 billion industry, that’s quite the task.