PREFIX myfn: <java:com.ldodds.sparql.> 
PREFIX geo: <http://www.w3.org/2003/01/geo/wgs84_pos#>
PREFIX locative: <http://locative.net/2004/packet#>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
SELECT ?media ?lat ?long
FROM <http://rdfweb.org/people/danbri/media/2005/08/2005-08-10-walk.rdf>
WHERE 
{
  ?x geo:lat ?lat;
     geo:long ?long;
     locative:media ?media.
  FILTER (myfn:Distance2(?lat, ?long, "51.374852"^^xsd:double, "-2.382584"^^xsd:double) > 18)
}