Many Google map mashups don't fall under any common category. Some of these miscellaneous mashups are entertaining, some are informationalbut they're all quite interesting.
PackageMapper.com (www.packagemapper.com) One of the most useful mashups I've found; it maps FedEx, USPS, and DHL packages en route to their destinations, as shown in Figure 19.19
Figure 19.19. Tracking packages via PackageMapper.com.
Area 51 Satellite and Aerial Photos (gmaps.tommangan.us/groom_lake.html) Find out what's really going on at that top-secret government site
Spacecraft Tracking (gmaps.tommangan.us/spacecraft_tracking.html) From the same guy who did the Area 51 mashup, this one goes into outer space to track the orbits of the Hubble space telescope and the International Space Station
The Big One (www.ducklet.com/earthquake/) Uses map mashups to create a simulation of the great San Francisco earthquake and fire
What Time Is It? (www.gchart.com) Click anywhere on this map to find the current time for any location in the world
MapSexOffenders.com (www.mapsexoffenders.com) Zoom in to find the location of registered sex offenders across the U.S.