ESRI’s Geography Network and Tele Atlas are handy. A PDA, phone, pager, onboard car navigation system, or wireless Web-enabled laptop can query for “the shortest route to an address,” or “all gas stations in a 10-mile radius.” Based on the location of the device, a list of requested services is provided and a detailed route.

Maps.yahoo.com and Map Info servers do it, of course, but with portable GPS, E-911 and location-specific “hot spots”, location-based services may become more popular. “Always on” connectivity could devolve into “spam as you go”. Or real-time tracking using MapObjects, Internet Map Servers, and CDPD/GPRS networks or satellite-based systems like CartaGen, which tracks ocean research vessels, may become common.

Geography Network has lots of free resources. Open GIS servers like U/Minnestota’s GIS server builds upon other popular OpenSource or freeware systems like Shapelib, FreeType, Proj.4, libTIFF, Perl and others. Minnesota’s Recreation Compass runs on a free Open GIS server.

A 3D map of the world with 30-meter resolution was created by the Shuttle Radar Topography Mission. Over 11 terabytes of data, equivalent to 20,600 CD-ROMs was gathered. Today, i-cubed combines terrain data from DEM and satellite photos to create images with three-dimensional qualities. Earthviewer, in turn, merges i-cube’s US mosaic and AirPhotousa in their products. Digital Earth prototypes may point to the future - These icons link to social bookmarking sites where readers can share and discover new web pages.