A new, location-based web service is trying to make social-networking software more about socializing than simply collecting lists of buddies.

Meetro, from a small, Chicago-based company called Meetroduction, marries instant-messaging software with geo-proximity technology in the hopes of expanding people's social circles.

When you sign on and report your location, Meetro's Windows-only software displays the names and photos of users within a certain geographic radius of your address. You can then check out what music and books someone likes, according to their profile, and instantly start chatting, or invite them to join you for coffee a couple blocks away.

Dating and making business contacts are the most obvious uses of Meetro, according to Meetroduction CEO Paul Bragiel. But he hopes the service will smooth the process of making new friends.

"Ten years ago, the idea of dating people you met off your computer was ridiculous, but now it's commonplace," Bragiel said. "Ours is the next bump. People right now are meeting over computers and plan to meet each other. Meetro is dynamic, so if someone shows up in your local area, you can meet up in 10 minutes because they are less than a quarter-mile away."

Meetro users currently are clustered mainly in Chicago and New York City and mostly seem to be 18- to 30-year-olds, college students and people new to a city who are looking to socialize.

Bragiel says his company is very aware of privacy issues and works to make sure Meetro does not turn into stalkerware.

For starters, the software generalizes locations, so a user can know that someone is within a mile, but won't get a specific address. Meetro users can also prevent someone from ever seeing their profile or IM-ing them again by hitting a prominently placed "block" button.

Meetro isn't the only location-based social-software application, though nothing else works quite the way it does.

Google recently acquired dodgeball.com, a service that lets you use SMS to broadcast your location to nearby friends. A Germany-based company called Plazes that lets people report their location and contact information is drawing in Silicon Valley technologists. And several large cell-phone providers offer a service that lets you know the locations of friends on the same carrier.

Many Meetro users' first chat invitation comes from the service's unofficial ambassador, Jean Zei, a 31-year-old office manager who goes by the handle "QueenJean" and makes a point of welcoming new users. Zei says that, despite having made dozens of new friends, she has had to block three users permanently.

"Like anywhere else, there's some weirdos out there that I block just because I don't wanna look at them," Zei said in an instant message. "But otherwise, the crowd is so fun and welcoming and inviting."

Kurt Uhlir, a Chicago technologist who edits a blog called The Technology Suits, is looking forward to Meetro having enough users that he can easily find people nearby who share his interests.

"I have already met a few people while in downtown Chicago, once at a flight delay in O'Hare and another time in Atlanta for a layover where I met someone just to talk to for a while," Uhlir said. "I have even kept up with one of those guys since for business reasons and we bounce ideas around about advertising models."