Programmable Web had a post a couple weeks about announcing the 5th birthday of the first web mashup:
Five years ago Paul Rademacher reverse engineered Google Maps to put Craigslist homes and rentals on a map on his site. The site essentially pre-launched the map mashup category, because there was no Google Maps API at the time. Even now, Paul’s HousingMaps.com is the prototypical example mashup and still used by many to find their new homes (and our HousingMaps profile is of course one of the first mashups added to our directory back in 2005). Since then, as we’ve seen, the Google Maps API has gone on to be the most popular API to use.