ptiger is a Tcl/Tk/Tkgeomap script that uses wdgeomap to display U.S.
Census Burea populated places on an interactive geographic map.

To run it, type ptiger on the command line. After a few seconds, a map
should appear. Adjust the view by Dragging or Double-Clicking. As the
cursor moves, a label below the map displays the cursor location and
the azimuth and range from the + marker to the cursor. Move the + marker
by Right-Double-Clicking. The map has dots at places with population
greater than a user selected threshold. Moving the cursor over a dot
labels the place with its name and displays the population in another
label below the map. In addition to the wdgeomap menus, a Places menu
enables adjustment of the population threshold and dot size. There is
also a Find menu that does a case insensitive regular expression search
for a named place.

WWW: http://www.tkgeomap.org/ptiger.html