The PBDB Navigator is a map-based interface to the Paleobiology Database, which among other things includes the locations of every fossil find. A map of every fossil site seems straightforward enough, but there are hidden depths to this one: you can filter by taxonomy (want to look up the fossil sites for eurypterids or tyrannosaurs? no problem!) or by geologic period, but what’s especially neat is that you can factor in continental drift: when searching by geologic period (the Permian, for example), you can show the continents as they were positioned during that period (see above). More at Popular Mechanics. [Leventhal]