geo
Links
http://exogen.case.edu/projects/geopy/, geocoding toolbox.
http://www.qgis.org/ (recommended by Marcus)
https://grass.osgeo.org/ (recommended by Marcus)
Install
easy_install geopy
Sample
>>> from geopy import distance
>>> millhouse = (30.82079429295863, -3.8382625579833984)
>>> moorview = (30.8301739931749, -4.084231853485107)
>>> distance.distance(millhouse, moorview).miles
10.788581582926698
>>>
>>> mycompany = (30.529211010033244, -3.603794574737549)
>>> distance.distance(moorview, mycompany).miles
29.630815697451709