Although he hasn't heard of anyone using the site for planning a trip, he has gotten emails from office workers near the rail line exclaiming that trains have appeared outside their windows at the same time they appeared at the same location on his map.
"Even the most casual of Web site creators can get started relatively easily and have something to show in minutes," McNamara said.
Such ease "allows people to bring their ideas to life," he says.
Other Web services make the job of customizing maps even more straightforward.
A Web site called Platial allows individuals without any programming skills at all to build personalized maps.
Users fill in an address or click on the map where they want to add a marker, and the site automatically adds a pointer on that spot. Then they simply fill in the details, such as text and photos, of what makes that spot unusual.
Platial co-creator Di-Ann Eisnor, who coined the term "neogeography," says she and fellow creator Jason Wilson got the idea for the site after returning from an extended stay in Amsterdam, the Netherlands.
When the pair had out-of-town visitors, they created hard-copy maps detailing local sites to see. But once the pair was back in the United States, their maps were of little value.
"We pined for a way to keep them in a more permanent fashion, and to make them more sharable," Eisnor said.
"We hope [Platial] will grow into something with millions of points of interest plotted by thousands of users around the world," she continued.
Already the free site has several thousand registered users who have mapped more than 200,000 places. Anyone can look at the maps others have created.
At first, participants will typically map where they live, where their friends live, or where they went to school, Eisnor notes.
Eventually, though, the mapmakers may design diary-like maps detailing places they visited, or "become local guides" by pointing out places of interest.
Sacramento, California, resident Guinness Wieland created a Platial map to pinpoint great breakfast restaurants in her hometown.
"I had just returned from one of my frequent breakfast outings when I read about Platial. I just wanted to test it out," Wieland said.
"Turned out it was fun to use, and I've been updating it regularly ever since." She is now exploring Sacramento eateries she hasn't been to so she can continue making updates.
Chicagocrime.org plots crime reports published by the Chicago, Illinois, police department, mapping incidents by street, date, zip code, or other categories.
"No longer will people have to think, Oh, where was that place we went to in Peru," Platial's Eisnor said. "In addition to keeping it [on a map] so you'll remember, you can share it with your friends or other people going to Peru."
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