[mathias_10gen]

I don't know exactly what your GIS needs are, but it might be worth seeing if MongoDB's geospatial indexing meets them if you are interested in querying free-form data.

http://www.mongodb.org/display/DOCS/Geospatial+Indexing http://www.mongodb.org/display/DOCS/Geospatial+Haystack+Inde...