Map hacks have been around for a couple of years, but the real revolution in online mapping is much more recent — and involves the ability of amateurs, rather than programmers, to create maps using online tools. That’s the argument in this article in yesterday’s New York Times:

[T]he Web mapping revolution began in earnest two years ago, when leading Internet companies first allowed programmers to merge their maps with data from outside sources to make “mash-ups.” Since then, for example, more than 50,000 programmers have used Google Maps to create mash-ups for things like apartment rentals in San Francisco and the paths of airplanes in flight.

Yet that is nothing compared with the boom that is now under way. In April, Google unveiled a service called My Maps that makes it easy for users to create customized maps. Since then, users of the service have created more than four million maps of everything from where to find good cheap food in New York to summer festivals in Europe.

The article adds some non-Google stats as well: a million maps using Microsoft’s older Collections; 40,000 maps through Platial; 1.3 million traceroutes through MotionBased; 25 million geotagged Flickr photos. The upshot is: a lot of stuff is being mapped — and we’re the ones doing it.