Maptech's MapServer is free. You can view, mark locations with an icon, link the icon to any URL, save your icon's location in your personalized "My Maps," and share that with a friend or colleague.
Also, print and e-mail USGS topographic maps, digital orthophoto quadrangles, aero charts and NOAA nautical charts online. Maptech's MapServer allows access to the largest online database of NOAA digital charts and USGS maps available in the world.
Changing seasons as viewed from space in infrared.
Satellite imagery is sometimes supplemented with aerial photography, which has higher resolution, but is more expensive per square meter. Satellite imagery can be combined with vector or raster data in a GIS provided that the imagery has been spatially rectified so that it will properly align with other data sets.
The Amazon Hope medical project is run by The Vine Trust and Scripture Union Peru (partner organisations) to provide health services to some of the poorest and most isolated communities in the Peruvian Amazon.
Trimble Outdoors and leading national publications—BACKPACKER, Bicycling and Mountain Bike magazines—is now provide Premium GPS-based information as a Google Earth Featured Content Layer.
This multimedia GPS content layer allows Google Earth users to access a wide variety of data on fitness and outdoor adventures, including routes, GPS tracks, points of interest, trailhead directions, trail descriptions, photos, video and audio clips.
A Google Earth user can view a 3D trip of running, bicycling or hiking destination. For example, hikers can experience the Pacific Trail online by viewing hundreds of photos, audio clips and videos from BACKPACKER Magazine through Google Earth.
Google Earth users can export the layer data to any WAP-capable mobile phone, experience it via a GPS-enabled mobile phone with Trimble Outdoors' fitness and outdoor recreational applications, or download to a stand-alone GPS device. 
