The images below are made with a freeware program named "Radio Mobile", written by an amateur radio operator named Roger Coudé VE2DBE.  I have found some pretty amazing software written by other HAM's, but this one is definitely in the "All Time Top 5"

Radio Mobile uses a number of different data sources, most of them available by a free download from the US Geological Survey web site.  The two images below were created using the newer, high resolution "SRTM" data feeds.  Starting on February 2000 the Space Shuttle Endeavor began gathering topographical data using the SRTM radar, the "SRTM" acronym is for "Space Radar Topography Mission".  With its radars sweeping most of the land surfaces of the Earth, SRTM acquired enough data during its ten days of operation to obtain the most complete near-global high-resolution database of the Earth's topography.  To acquire topographic (elevation) data, the SRTM payload was outfitted with two radar antennas. One antenna was located in the Shuttle's payload bay, the other on the end of a 60 meter (200 foot) mast that extended from the payload pay once the Shuttle was in space.

This data is available from a number of locations, the best is the US Geological Survey web site at: http://srtm.usgs.gov/index.html  If you are interested you can read more about the SRTM gathering on the Jet Propulsion Laboratories web site at: http://www.jpl.nasa.gov/srtm/cbanddataproducts.html  In short, you down load the region of the country you are interested in, then use the Radio Mobile program to import the data.  Once imported you will have the ability to create very detailed, two-dimensional topographic maps.  These maps will show the terrain altitude differences by varying colors to designate height.  Once the terrain data is imported, you add your stations and define the radio variables such as antenna height, db Gain, power output, etc.  Once this is done you can have the program render the image which can be saved to a "JPG", or a "BMP" format.

For a HAM operator, the possibilities with this program are endless.

To download the Radio Mobile program or to read about it go to:    http://www.cplus.org/rmw/english1.html
For SRTM data, visit the USGS web site at:                                    http://srtm.usgs.gov/index.html

There are some additional links at the bottom of this page...

Whitney Mountain, Northeast Benton County Long: 093 56' 28" Lat: 36 23' 33"
440MHz, 5db Gain Antenna, at 10 watts PEP

Bentonville Arkansas Map Centered on City, View from 100km
This image was HUGE! (1400X1050) and the detail was great!  I scaled it down for the web

Free US at 1 and 3 arc second resolution (30m or 100 m)

    Get SRTM data via ftp at Shuttle Radar Topography Mission (SRTM) data products

Free Continental US at 3 arc second resolution (~100 m)

    Get DEM250 elevation data (3 arcsecond) via http at WWW EDCFTP or via FTP at FTP EDCFTP using DEM 250 to DTED converter to convert it to DTED
    or simply go to Virginia emergency network where the data is ready to use!

Free World at 30 arc second resolution (~1km)

    Download elevation data (30 arcsecond) at National Imagery & Mapping Agency.
    The program can also read GTOPO30.

Canada at 3 arc second resolution (~100m)

    Convert Geomatics Canada DEM to DTED using DEM 250 to DTED converter (VB6 runtime required)

Free Canada at 30 arcsecond resolution (~1km)

    Download from Geomatics Canada and use the Cadada3D visualization software (English version)