Geocoder is a library for Ruby developers and a command-line utility
that helps with converting street addresses (U.S. only for now, I'm
afraid) to geographic coordinate pairs, specifically, latitude &
longitude.

http://rubyforge.org/projects/geocoder/

Read the docs at:

http://geocoder.rubyforge.org/

The library is useful for developers who want to incorporate geocoding
into their Ruby applications; the command-line utility, `geocode', is
useful for one-offs, shell scripts, and non-Ruby apps.

The library is a wrapper for various geocoding web services. The two
services currently utilized are 1) Yahoo! Maps Geocoding API, and 2)
geocoder.us (looking your way, GMaps!).

CLI example:

$ geocode "1600 pennsylvania ave nw washington dc"
Latitude: 38.8987
Longitude: -77.037223
Address: 1600 PENNSYLVANIA AVE NW
City: WASHINGTON
State: DC
ZIP Code: 20502-0001

-Paul

--
Paul Smith
aim: thaislump
Center for Neighborhood Technology
Technology Director, Wireless Community Networks
Chicago IL, USA