Possibilities for reverse geocoding might be given by the use of [Nominatim][1]. See there the section about "Reverse Geocoding / Address lookup" lookup". But you want the coordibates of a certain address? Then you have to meka sure that the given address is a certain point like a node in the OSM data. What coordinates should be given when no housenumbers are present in the OSM data, or the address is tagged to a (big) building? [1]: http://wiki.openstreetmap.org/wiki/Nominatim

Possibilities for reverse geocoding might be given by the use of [Nominatim][1]. See there the section about "Reverse Geocoding / Address lookup" [1]: http://wiki.openstreetmap.org/wiki/Nominatim