Just like that, two hanging ferns vanished from the front porch, the owner reported. A neighbor told of potted red geraniums disappearing from the entrance to a nearby house. A third wrote that someone had walked off with their impatiens that very morning.

Was a serial plant thief stalking Mount Pleasant?

The chatter took place not on a street corner or at the local supermarket but on the Internet, on a kind of virtual bulletin board that has become a ubiquitous part of neighborhood life across Washington.

Community Web sites and listservs, clearing houses of the arcane, are burbling just below the city's surface. There are alerts about yard sales, community meetings and lost pets. There are also impassioned discussions about local issues and services, such as recycling pickup (or its lack) in Adams Morgan, and the screech that the D1 bus makes in Glover Park when drivers put on the brakes.

In Columbia Heights, the arrest of the graffiti artist known as Borf inspired no shortage of commentary, including a recommendation of "severe punishment for all who take it upon themselves to take over and destroy public property."

To which someone replied: "All of you people on this list seem quite paranoid."

Then there are those listings that defy easy categorization.

A Cleveland Park woman requested referrals for a "cat therapist" after her feline took to regularly urinating on her couch when a certain man came to visit.

"And if you know a handsome, forty-something guy, I'll take one of those, too," she wrote.

Joseph Malherek, a Public Citizen policy analyst, posted a message last month after hearing gunshots near his Columbia Heights apartment. After more gunfire five days later, he went on the Web site and declared, "I think it's time to leave this place."

In a telephone interview, Malherek said that he regularly checks out the Columbia Heights postings to get a "sense of what's going on in the environment that surrounds me."

"You experience things, and you don't have a way to communicate with the people you see every day," he said. "It's a forum for that. It's nice to know that the things you experience -- hearing those gunshots, storms, racial conflicts in the neighborhood -- it's not just affecting you, it's a community thing. It provides a sense of community."

Josh Gibson, an advisory neighborhood commissioner in Adams Morgan, said there was never any question about how he would announce his recent decision to relinquish his seat. He went directly to the Adams Morgan listserv, which he created in 1999.

"There is no better or faster way to target 1,500 key Adams Morgan residents," Gibson said. "It's required reading for neighborhood politics and business."

In recent years, more than two dozen neighborhood Web sites have cropped up across the District, from Brookland's listserv, which has just more than 1,000 members, to M. Marie Maxwell's homespun blog that covers issues relating to the eastern edge of Shaw. There are Web sites devoted to Foxhall, Georgetown and Petworth. There is Elise Bernard's blog for the Trinidad neighborhood, including photos of stray cats and talk that Harris Teeter is mulling over a move to Third and H streets.

A few sites seek a broader view of the city, including DCist, a Web site that features a daily news and sports roundup and reviews of rock bands, trendy restaurants and cafes. "Good morning, Washington. There's a 70 percent chance of showers today in both the morning and afternoon, so remember to bring along an umbrella," the site announced one morning last week.

Rob Goodspeed, 23, who develops youth programs for People for the American Way Foundation, started DCist a year ago, after concluding that young professionals in the District were yearning for a Web site devoted to the city.

"There's a void of information," said Goodspeed, who oversees a volunteer staff of five editors and 30 writers who put in a few hours a week, sometimes more. "It's very difficult to find your way around the city if you're an average young person."

Many of the neighborhood sites are Yahoo listservs, in which members can read and post e-mails on an array of topics. Among the largest is Cleveland Park's listserv, which was founded in 1999 and has more than 3,000 members. Bill Adler, 48, a writer who started the site with his wife, Peggy, said they hoped it would "be just like walking into the supermarket and post office and talking to your neighbors."

At first, the Adlers imposed few rules. There were lively discussions, such as when Giant Food sought to expand on Wisconsin Avenue, or when traffic congestion at the National Child Research Center private school spilled out into the neighborhood.

Sometimes the dialogue got unruly. When Elian Gonzalez, the Cuban boy who sought sanctuary in the United States, was staying in Cleveland Park, a slew of e-mails from Miami appeared on the site opposing his return to his homeland.

After that, Adler and his wife prohibited name-calling and mass e-mailing of news releases to members, and they stipulated that moderators had to review all messages before they forwarded them to the site.

"We work to make sure that the tone has a neighborly feel to it," he said. "People can criticize, but only over substantive matters."

Several years ago, Laurie Collins, 52, a systems engineer, created a Web site for her Mount Pleasant community that has nearly 900 registered members. Recent topics of discussion on the site have included development projects and rumors that President Bush's daughter, Jenna, had applied for a job at a neighborhood charter school.

"One thing about people in Mount Pleasant is that they hate to go to meetings," said Collins, a former advisory neighborhood commissioner. "They will not go to a meeting unless there's something catastrophic, like murders and robberies. This fills a void in the sense that people can express how they feel, give their opinions and not have to be at a meeting."

Bob Kohlmeyer, 23, a government affairs coordinator for a trade association, acknowledges that he had a less civic purpose when he started a Glover Park listserv a few months ago. He hoped to meet women.

For months, he said, he had been riding the bus to work and noticing attractive women on board. At work, he posted messages about the women in the "Missed Connections" section of Craigslist and discovered that there were others who had come to the same conclusion, including women who had noticed attractive men.

So Kohlmeyer started the listserv in May and tried to arrange a "Bus Crush Happy Hour." Fifteen people showed up, many of them not from the bus.

Kohlmeyer said he has yet to get a date from the listserv, which has about 150 members. But something else has happened: The site has become a forum for discussion of community issues. On a recent night, a few members -- alerted to the issue by the site -- showed up at an Advisory Neighborhood Commission meeting to support a new tavern seeking a liquor license.

"It has become like a big bulletin board, more than a waiting room," he said. "It's a way to share information."

When she started her blog in 2003, said Maxwell, an archive specialist at the National Archives, she was mostly concerned with writing about herself and her life in the eastern edge of Shaw near Truxton Circle. Then after she was able to accept postings, readers began writing in and sharing their observations about topics, including gentrification, crime and the best places to buy liquor.

"The blog is me complaining and me being me," Maxwell said.

Apparently she has fans. Her site, she said, receives some 450 visits daily. Recently, she announced that she would reduce from five to three the number of days when she posts ruminations, in part to lighten her workload.

"Fear not, I'm not going anywhere," she wrote. "Neither are the crack heads, the dealers, the bad section 8'ers, and horrid suburbanites who come in to trash the hood. As long as there are those folks, as well as the slow changes of a gentrifying neighborhood, I'll write about them."

Laurie Collins and Jamie Treworgy check to see what members are writing about in Mount Pleasant's online forum.Between her job at the National Archives and posting messages on her neighborhood blog, M. Marie Maxwell finds time for her backyard garden in eastern Shaw.Many neighborhood sites, such as Cleveland Park's, are Yahoo listservs, in which members can read and post e-mails on many topics.M. Marie Maxwell, founder of a neighborhood blog, posts a review of the book "Lost in the City" by Edward P. Jones in her eastern Shaw home, above. Laurie Collins and Jamie Treworgy, right, discuss how Mount Pleasant's blog keeps their neighbors informed.