Not long ago, London resident Christine Tomas received a text message through her cell phone from a stranger who shared her belief that George W. Bush is an alien.
That unlikely moment presaged more texting, about movies, and eventually led to Tomas finding a long-term salsa dancing partner.
Tomas is a heavy user of Playtxt -- a cell-phone service that connects people nearby who have stated similar preferences.
Across the pond, in New York, Diane McGunigle used another service, dodgeball.com, as the lubricant to introduce herself to someone she saw on the subway but had been too bashful to talk to.
"I checked in to dodgeball," she said, and "I got an alert that 'so-and-so has a crush on you, and he is at X bar, go and say hi.'" she said.
So McGunigle went to the bar, and by coincidence, it was the same guy she'd just seen on the subway. Like her, he'd been too shy to make an approach, but not to send a text message.
"I now had a valid and less-frightening excuse to meet him," McGunigle said.
Dodgeball and England's Playtxt are two examples of mobile social-software services, otherwise known by the catchy acronym, MoSoSos.
And Tomas and McGunigle are the kind of enthusiastic users who MoSoSos hope will evangelize for them and build their services by word of mouth.
MoSoSos are the mobile equivalents of online social networks like Friendster and LinkedIn. They help users find old friends, or potential new ones, on the go.
Typically, users set up a profile listing interests, hobbies and romantic availability. They also state what kind of people they'd like to meet. Because the service is tied to a mobile device, it knows when people with similar interests are near each other.
Not surprisingly, MoSoSos are ideal for hooking up young, active professionals tied to their mobile phones or laptops, and they're starting to take off. Here are some of the leading players:
Dodgeball: Currently rolled out in 22 U.S. cities, and with about 15,000 users, dodgeball is the American MoSoSo standard-bearer.
It works, explained founder Dennis Crowley, by having users check in with text messages announcing where they are. Then, because dodgeball maintains a database of hundreds of nightspots in each city, anyone on a user's friends list who is within 10 blocks gets a message that his or her pal is nearby.
The service also has a "crush" feature. Users view profiles of other members and designate ones they'd like to meet. If the object of a crush is nearby, he or she gets a message to that effect. The system maintains privacy by identifying users only by screen names.
"I can't tell you how many people I've met through this," said McGunigle. "It has not only simplified my socializing habits, but has allowed me to meet people I would not have met otherwise."
Playtxt: Playtxt's 6,000 members key in the postal code where they want to be found when they're on the go. Then, like dodgeball, anyone can see which friends, or friends of friends, are within that postal code.
Friends can send messages to each other directly on their mobile phones, but potential friends -- matched through their profiles -- can only send messages using screen names. And the service also allows for privacy settings so users can hide from annoying ex-lovers, said founder Andrew Scott.
"I was slightly intimidated at first, because I wasn't sure what kinds of people might end up contacting me," said Tomas. "The whole Kevin Bacon six-degrees-of-separation thing really helped. If I get a text from someone, I can reply with a '?' and it sends me back more information about the person."
Jambo Networks: Launched at last month's Demo conference, Jambo utilizes Wi-Fi hotspots to connect its members, who join through their university, workplace or affinity group like an alumni association. The service determines if anyone logged onto a hot spot with a Wi-Fi-enabled laptop, PDA or smartphone is a member of the same group. If there's more than one, each person sees the other's profile, which, among other things, highlights similar interests.
Following the MoSoSo model, Jambo facilitates pseudonymous messaging between the two users, who then decide if they want to introduce themselves.
Laura Chauvin, assistant vice chancellor for alumni relations at Washington University in St. Louis, recently signed up her school as a Jambo customer. Now, students and alumni can use Jambo to connect with others at the university with similar interests.
"We thought this would be a useful way for students to make connections with each other," said Chauvin. "We believe the more you're connected to your classmates ... the better your chances for career success and academic success."
Jambo also makes it possible for two members of the same group to connect even if there's no hot spot nearby. It sets up an ad hoc peer-to-peer network allowing users to discover one another on airplanes, parks or cafes.
Plazes: Based in Germany, Plazes revolves around the idea that anyone with a Wi-Fi-enabled laptop can define a "plaze." A plaze is usually a Wi-Fi hot spot. It tells where the user is located and looks for other members nearby.
When a user detects another member, the system displays similar interests, and like other MoSoSos, enables communication. The service also shows members when their friends are in other plazes, a feature that encourages people to move from one to another.
In big cities in Europe or the United States, co-founder Felix Petersen said, there is a good chance of finding another member in the area.
"Geographically, mobile messaging is maturing and finding new groups of users beyond the initial curious," said Judith Meskill, a social-networking expert. "People are now beginning to get how amazingly valuable this is to their lives in motion."
At present, most MoSoSos are relatively small, and a service's members can only communicate with other members of the same service.
But Meskill thinks MoSoSos are a natural fit for universities or groups like the American Cancer Society.
"Passive social-networking services that merely aggregate our friends, and their friends, ad infinitum, eventually lose their luster," said Meskill. "Geographically mobile solutions that help us connect with our affinity groups or friends are infinitely more sticky."
