Check this google api to generate a map

URLExecute["http://maps.googleapis.com/maps/api/staticmap", {"center" \
-> "51.5,5.4", "zoom" -> 12, "size" -> "800x500", 
  "maptype" -> "roadmap", "scale" -> 2, 
  "markers" -> "color:blue|label:C|51.5,5.4" , 
  "path" -> 
   "color:0x0000ff|weight:2|fillcolor:0xFFFF0033|51.5,5.4|51.45,5.35|\
51.5,5.45|51.5,5.4"}, "Method" -> "GET"]

The most important part is the "scale" parameter. This increases the number of pixels returned. Options are 1 or 2 (4 if you subscribe).

GeoGraphics uses openstreetmap. But GeoGraphics does not have a scale parameter. Anyone for a workarround to get higher resolution maps.