Matt Fox at Google Earth Library has just created a very impressive topographic map overlay for New Zealand. The imagery is lined up perfectly, and amazingly sharp.
Matt grabbed all 455 maps from the Land Information of New Zealand and converted them to a seamless overlay. As he mentions on the site, the images are a bit slow to load because they’re so sharp. After you load the KMZ file, give it a minute or two to get everything loaded in.
Try try it for yourself, just grab the KML file and then fly down to New Zealand.
Matt’s GE Library also has many other collections of large datasets for viewing in Google Earth. He also has topographical overlays for the entire US from the USGS.
Great work Matt!