I talked with a number of other people and projects at the conference that were collecting data and sharing information.  Your Mapper currently shows all its data through KML overlays with can be queried by location and other parameters for inclusion in other mashups.  We will be releasing an API, which at first is really just documenting these existing features.  And we support open standards and posting full, queryable datasets on public sites through the omgstandard.com.  That way anyone can grab and use the same data that we are using for their mashups!