ABOUT 18 people were gathered in the San Francisco offices of Urban Mapping, a company whose mild-mannered founder, Ian White, described its business model to me as "selling polygons." Instantly, I felt at home. I was among the geowankers, a group of high-tech map enthusiasts whose areas of expertise range from making customizable web maps (often built out of polygons) and geolocation software to map-based online storytelling and handheld devices that provide information about your environment as you walk through it.

Imagine getting a tour of San Francisco's Mission neighborhood via your smart phone, which pops up information about who painted the cool murals you're looking at in Clarion Alley, as well as which cafes are in the immediate area. Now imagine using that same phone to upload pictures you've taken of the cappuccino at Ritual to your blog, complete with a map showing the exact GPS coordinates of this excellent cafe. If anyone is going to invent that device, it's going to be a geowanker.

All of us had heard about this meeting via the geowanking email list, founded by überdork Joshua Schachter, where map geeks of all stripes have been engaging in banter and mad science for over three years. Tonight was the inaugural San Francisco geowankers meeting, and it was the first time many of us had had a chance to meet each other in person.

The evening was to be an informal eat-and-chat, with presentations from Rich Gibson, co-author of the astonishing Mapping Hacks, and Mike Liebhold, a brainiac from Institute for the Future, who said (only half-jokingly) that he wants to invent a "Tricorder for planet Earth."

Rich told us that he's currently thinking about how to use technology to deal with the "probability characteristics of space." In other words, how do you create an accurate high-tech map that reflects the fact that a given geographical location has a high probability of being referred to as "the Mission," but at least 10 percent of the time might be referred to as "Noe Valley"?

This kind of question might sound silly if you look at neighborhoods purely as a creation of real estate companies who have rigid ideas about where the Mission ends and Noe Valley begins. But geowanking is all about making maps democratic and creating representations of space that reflect ordinary people's lived experiences.

The idea of letting a real estate agency call the shots on where your neighborhood's boundaries are is absurd to a geowanker. Why not just build a digital map in layers so that you can see the real estate-defined neighborhoods, then click into another layer that shows what ordinary people on the street think are the boundaries, then move to another layer to see where all the rivers run underneath the city?

Mike pointed out that as more and more people start creating their own maps and putting them online, we're going to need to invent a system where we know which maps are "trusted," and which are just somebody rambling about how there are many paths to Blue Bottle Coffee from the Haight. Everybody began speculating about a not-so-distant future when you'll subscribe to somebody's map data the way you might subscribe to an RSS feed (and in fact, thanks to smartypants Mikel Maron and pals, there is a geoRSS format). Some feeds would be trusted and some wouldn't.

Then we got sidetracked by potential problems. What happens when the map democratization process goes nuts, and so many people are tagging places on digital map services that the spatial data is a mess? And what about map spam, where people buy ads on (for example) Google Maps, and suddenly your nice map of the Mission is covered with flags advertising Wells Fargo ATMs and places to buy Bud?

When the conversation wound down, we broke for wine and cookies. I got a chance to chat with Anselm Hook, the hacker who prototyped build-your-own-map service Platial.com. Platial is a mashup of Google Maps and allows you build and store customized maps that you share with friends (try it! it's insanely addictive). Anselm said his newest obsession is trying to create maps with "near instantaneous information," kind of like instant messaging and Google Maps rolled into one. "Imagine saying to somebody online, 'I'm here, what should I do?' and getting an instant reply with a map," he enthused. "That's what I want."

At last it was time to go and I headed out into the South of Market area, wishing I had Anselm's device so I could find a local restaurant, and wondering what the probability might be that somebody else would call this neighborhood Mission Bay.

Annalee Newitz ([email protected]) is a surly media nerd who became a geowanker because she's always getting lost.

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