Happenr is a new events search engine for Europe. The site scours thousands of European tourism, town, and cultural websites in search of upcoming events, and is available in English, German, and Dutch.
It is possible to search the events database via Google Maps. Each event is tagged on the map and clicking on a marker link will take you through to the details of that event. Happenr comes with its own API so other map developers may also be able to tap into this huge events database.