Mashups are probably one of the great assets of web 2.0. The capability of letting several online applications interacting with each other to create new services that profit to both the basic application owner and the mashup creator. Google Maps is certainly the best example for letting users generating successful mashups. By opening their API, they have openend the door to let people's creativity explode, thus promoting the service.

The first well-known mashup was conceived even before Google publicly opened their API for Google Maps, it was the Chicago Crime Maps, which is now closed but has been the first to input data into Google Maps to let people visualize where and when crimes happened in Chicago, helping them to chose a neighborhood to live in.

With Swisstrains, a moving map of the train traffic in Switzerland, we may have entered a new era of mashups. Although it is not yet live, the creator of the mashup promised to try getting GPS data to get the real location of each train and stop depending on the schedule.