In this photo taken Thursday, May 3, 2012, a woman walks past a vacant office building on Market Street near Twitter's new headquarters in San Francisco. With Twitter’s new headquarters set to open there soon, residents of a San Francisco neighborhood notorious for crime, drugs and homelessness remain among the least likely to have any way to send a tweet, much less access to basic goods and services. At a recent weekend “hackathon,” engineers and entrepreneurs sought ways to use tech to help people in the Tenderloin and Mid-Market Street area find food, housing, healthcare and jobs. In the process, city leaders hope to ease tensions between needy locals and newly arriving startups flush with cash. (AP Photo/Eric Risberg)

(AP) -- On the foggy streets of San Francisco, tech superstars and the homeless can be hard to tell apart in their identical hoodies. But there's a key difference: smartphones and cash in some pockets, neither in others.

These two crowds will soon find themselves even closer together when Twitter moves its headquarters into one of the city's poorest areas later this year, drawing attention to the divide between the tech haves and have-nots that crops up whenever wealthy companies rub shoulders with communities that haven't seen the benefits of the latest boom.

Still, optimism reigns in San Francisco, especially when it comes to the promise of technology to improve people's lives.

Recently, a crowd of such optimists came together for a "hackathon," a weekend of intense work and little sleep, as part of a nonprofit project called Creative Currency. Engineers and entrepreneurs joined with designers and neighborhood advocates to figure out how technology could help people in the Tenderloin and Mid-Market areas of the city who don't have roofs over their heads, much less web browsers.

"All people need dignity, right? And the base of dignity is being able to recognize and feel like you're part of humanity," said Aynne Valencia, a San Francisco designer who has worked for some of the biggest tech companies.

Over the weekend, Valencia and a team of 19 others designed a mobile wash station that people could use to take showers and launder their clothes. The project, RefreshSF, would be funded through small donations made via text message to pay not just for the wash stations themselves but to employ attendants who would ensure the stations didn't suffer the same foul-smelling fate of so many San Francisco public restrooms.

Young urban professionals risk coming across as patronizing when they come into neighborhoods they might otherwise shun -and they also risk failure if they don't understand how the neighborhood works.

To pre-empt that problem, Creative Currency organizers prior to the hackathon surveyed about 20 community organizations, 155 residents and 37 local businesses to gauge the neighborhood's needs.

"It was actually really great to be reached out to," said Kristen Growney Yamamoto, co-executive director of the Glide Foundation, one of the city's largest providers of homeless services.

Another proposal, Bridge, intends to solve what Yamamoto and others described as one of the most maddening problems faced by San Francisco's homeless. To get a bed for the night, shelter-seekers must line up early in the morning to get their names entered in the city's reservation system. Standing in line can take hours. Even then, a spot isn't guaranteed - most don't find out until early evening whether they have a place to sleep.

Barry Roeder, a San Francisco management consultant, wants to eliminate the lines by creating a neighborhood-wide network of touch-screen kiosks where people could make and check reservations themselves. The system could also notify people by text message if they received a bed - the Creative Currency survey found that while few residents have smartphones, about 60 percent have access to some kind of cell phone.

If Bridge works as hoped, the idea is that by freeing up people's time, they'd have more chance to do things to help themselves, such as look for work.

Before that can happen, Roeder acknowledges several challenges would have to be overcome.

"The nightmare that comes to mind is a busted ATM that's been graffitied and peed on," he said. Even tougher, said Yamamoto, would be the labor involved in grafting the system onto the city's existing archaic reservation network or building a new one from scratch.

Jake Levitas, research director at the Gray Area Foundation For The Arts, the San Francisco digital arts nonprofit that conceived Creative Currency, believes that such obstacles are best surmounted by applying the hacker mindset to community issues.

In Silicon Valley-speak, the word "hacker" is more often used to describe someone who comes up with a clever solution to a frustrating problem rather than someone who's committing cybercrimes. Levitas says hackers in the positive sense of the term start from the premise that problems are solvable and then work quickly and cheaply to solve them, learning from their mistakes and trying again - what the startup world refers to as "iterating."

In a sense, he said he hopes the same mentality that has helped once-small startups to challenge the dominance of companies like Microsoft can make strides against a seemingly intractable problem like homelessness.

"I don't think anybody who comes to our events thinks that they're going to solve poverty in a weekend," Levitas said. "But I think they do think they can do something that contributes."

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