Remember the days before Craigslist, when newspapers made money from classified advertising?

In the year 2000, the U.S. newspaper industry brought in a high of nearly $20 billion dollars in classified revenue; by 2009, this figure had plummeted to under $10 billion. Meanwhile, the number of adult Internet users who visited online classified sites jumped from 22% in 2005 to 49% in 2009, according to findings from the Pew Research Centre’s Internet & American Life Project.

Since last fall, the Guardian Media Group has worked to recapture some of that lost revenue with n0tice.com, the digital answer to a community centre corkboard, which asks users, “what’s happening near you?” To post is free, but as with promoted Tweets, n0tice-ers can bump their bulletins to a privileged spot on the board for a fee.

Yesterday, in keeping with its commitment to open journalism, the Guardian Media Group released an open API for n0tice, offering publishers big and small not only the chance to dip back into classified earnings, but also “a free off-the-shelf solution to some of the digital newsroom’s current challenges including crowdmapping, mobile publishing, liveblogging and collaborating with users,” as explains the instructional site n0tice.org.

This platform takes advantage of the rising geo-tagging tide: according to another Pew research paper released earlier this month, as of February 2012 nearly three-quarters (74%) of American smartphone owners use their phones to get real-time, location-based information (up from 55% last May). With n0tice, posts from iPhones are automatically geo-tagged, so that users can track what is happening in their immediate viscinity, and journalists can see the big picture. The n0tice crowdmapping tool also captures users' location data, which can be embedded into a feed and used for a mapped visualization of user-aggregated content.

Beyond an attempt to bring classified earnings back to newspapers' barren coffers, the n0tice API is a generous offer pinned to the Internet’s bulletin board for a free online journalism toolkit, promising easy integration into just about any content managing system, that allows publishers (as well as businesses, developers and communities) to find new uses for the information residents of a particular area search for and share on a daily basis.

The Guardian has set the tone, using n0tice data to crowdmap the Olympic torch relay into London by slotting user-generated, location-tagged content into a custom-built interactive map (see picture below). Now, it passes the flame to the digital experimenters in newsrooms everywhere, challenging them to open their imaginations.

Sources: n0tice, Nieman Journalism Lab, Journalism.co.uk, Pew Research Centre (1) (2)