Now, what would it take to build an open-source clone of Craigslist one could run locally?

Craigslist Circles the Globe With Online Classifieds, One City at a Time
By ERIC PFANNER, International Herald Tribune
Published: January 17, 2005

LONDON – A motor scooter in Manchester, an apartment in Amsterdam, a poster in Paris. All are available via Craigslist, an online bulletin board that presents a new challenge to the established players in the estimated $100 billion global market for classified advertising.

Craigslist was started 10 years ago by Craig Newmark, an Internet pioneer in San Francisco, as a way of keeping friends up to date on events in the Bay Area. It spread through the United States before going international in 2003, with sites in London and Toronto. The expansion accelerated in late 2004 with a flurry of sites, including ones for Paris, Berlin, Tokyo and Sydney. About a dozen other international start-ups are planned in the next few months.