A long-shot I guess but maybe someone might fancy a crack at this? I have a 1:10,000 map data set of the UK as a series of TIF tiles (~30GB). This sort of detail... I had in mind a project to make use of this data, but my coding skills are pretty rubbish nowadays and I guess I'm looking for someone who may find this of value. Here's the idea... The data set as is, is pretty cumbersome and requires a front end to to make it usable. I've done a couple of tests and what works well is using the data set to overlay Google Earth with a transparent layer thus... Without overlay... With overlay... The overlay adds a shed load of detail to the aerial view and if you're into maps I think you'd agree it's pretty useful. This is what's required to achieve the above... <?xml version="1.0" encoding="UTF-8"?> <kml xmlns="http://earth.google.com/kml/2.2"> <Folder> <name>Ground Overlays</name> <open>1</open> <description>Examples of ground overlays</description> <GroundOverlay> <name>Large-scale overlay of North Leeds on terrain</name> <description>SE33NW</description> <color>80ffffff</color> <Icon> <href>SE33NW.jpg</href> </Icon> <LatLonBox> <north>53.85482965608011</north> <south>53.81177433565559</south> <east>-1.468904990738885</east> <west>-1.546792625617847</west> </LatLonBox> </GroundOverlay> </Folder> </kml> To make good use of the map data requires a small program that... 1) Allows say, user entry of a OS grid reference. 2) Select the correct tile(s) from the set (easy). 3) Generate the lat, long coordinates. 4) Create the KML file and run it (as above). If you want to see this working as a proof of concept, download these two files and bung them on your desktop (you need to have Google Earth installed).... https://dl.dropbox.com/u/2323104/overlay.kml https://dl.dropbox.com/u/2323104/SE33NW.jpg Just click on the KML file. Again I guess this is a long-shot but if anyone would like a bash at knocking up an app I'll post out the map data to you.