The idea of Open Data is not new and scientists have promoted free exchange of data for a long time. However, the term Open Data refers to the recent trend in informatics and geospatial sciences to provide geographic data free to use. Pioneers were particularly in the UK, US and Canada, where it has traditionally been claim that government geodata should be free. Vancouver for example launched a rather decent Open Data website. This initiative created many possibilities for various new location based apps such as the very successful Vantrash that gives inhabitants of Vancouver the current schedule for recycling and garbage pick-up.
Now, Berlin as first major German city has set up a website with government Open Data under http://daten.berlin.de/datensaetze and it is to hope that this will trigger similarly successful geospatial applications.