A last-minute baby sitter, a much-needed shovel or a possible ne'er-do-well may be just around the corner, and increasingly people are finding out about these things without venturing outdoors. Instead, they're hearing of them via online neighborhood networks.

Only 43 percent of Americans say they know either all or most of their neighbors, and as many as 28 percent of us have difficulty naming even one person on the block, according to data compiled by the Pew Research Center in 2009 and published in 2010. Cities across the country are looking for ways to boost neighborly interaction, and many have turned to the hyperlocal social networking site Nextdoor.

The San Francisco-based company has grown to serve upward of 28,000 neighborhoods since its 2011 debut. Now St. Louis Park joins Rose­ville and Edina as the third city in Minnesota to partner with the company.

"We've tried to focus a lot of our communication strategies to reach people wherever they're at," said St. Louis Park spokesman Jamie Zwilling of his city's decision to sign on to Nextdoor's city program. Zwilling said online platforms like neighborhood websites, Facebook and Nextdoor came up in crowdsourcing about city-resident communications.

"I think that this service is really good for connecting people with information about what is going on around them," said Kariann Gottesman, who joined St. Louis Park's online Fernhill neighborhood a few months ago.

The idea behind Nextdoor is to revitalize neighborhoods with a sense of community, said Nextdoor co-founder Sarah Leary. "I walked out my front door in San Francisco and knew one person on my street," she said. "It was out of sync with what should be happening." The website acts as a hub for neighbors to sell a couch, share a recipe or banter over local issues.

Already, many people receive text or e-mail alerts from their cities about nearby crime, but Nextdoor offers a greater depth of communication — one that is interactive instead of just informative.

"This is so much nicer. It's more far-reaching," said Nancy Bush, a member of Edina's Morningside neighborhood. Before accepting a friend's invitation to Nextdoor about a year ago, Bush had acted as neighborhood liaison, compiling contact information and e-mailing her neighbors with block-party invites and occasionally a more onerous alert about suspected crime.

Edina joined Nextdoor's city program last October, following a move by Roseville, which in April 2012 became the first city in the state to turn to social networking as a way to improve communication at the neighborhood level.

St. Louis Park now has 28 of 37 neighborhoods engaged in online networking after the city partnered with Nextdoor last month, according to Jennifer Burke, a Nextdoor representative. The metro area is home to about 700 neighborhoods that Nextdoor could serve, Burke said.

Part of the allure is that Nextdoor websites, which are free to use for both residents and cities, also are intensely secure and private, and the company does not share users' information with third parties — neighborhood websites are even bereft of advertising. Residents signing up with Nextdoor must verify their addresses with the company in order to enter the password-secured network. Only members of the neighborhood network can view postings; even cities, despite partnering with the company, can only see information that members post in response to a city's own messages.

'An icebreaker'

While civic issues, crime and safety take up a combined 42 percent of conversations on Nextdoor's websites, neighborhood commerce comprises 40 percent of all discussions, including asking for recommendations or buying and selling things, according to numbers provided by Nextdoor.

This market may open the door for an index of local businesses as part of the site, Leary said. This would offer a way for Nextdoor to engage small businesses and elicit a new revenue stream as the company moves beyond venture capital funding.

"The neighborhood is the original social network," Leary said, adding that Nextdoor, unlike networking behemoths Facebook and Twitter, "is a place where people understand that the context is around local issues important to them."

"Nextdoor really serves as an icebreaker and a modern way to get the conversation going," Leary said.

St. Louis Park said its primary aim in signing with Nextdoor was not so much to push neighbors to communicate with each other offline, but instead to better reach the population and to complement existing communication tools.

"We try and let our neighborhoods grow and manage themselves as organically as possible," St. Louis Park's Zwilling said. "We see our role, in the city, as a way to point people to different tools."

Even if things don't change on the ground, people may still benefit from online neighborhood networking. In neighborhoods that already maintain networking sites or neighborhood-specific blogs, people who don't know any of their neighbors are, surprisingly, just as likely to engage in online interaction with them as are their more garrulous counterparts who personally know most or all of their neighbors, according to the Pew Center's survey.

Gottesman said she hasn't yet seen any evidence of Nextdoor's effects popping up offline, though she also said that temperatures hardly hovering above zero may be countering any positive impact. Spring and summer may bring a different story.

Elizabeth Hustad is a University of Minnesota student reporter on assignment for the Star Tribune.