The least OO of all possible solutions.

ride4ruby.rb

# Ride4Ruby challenge
# details: http://www.engineyard.com/blog/2011/january-contest-ride4ruby/

require 'open-uri'
require 'JSON'
require 'pp'
require 'net/http'

States = %w{Alabama Alaska Arizona Arkansas California Colorado Connecticut Delaware District of Columbia Florida Georgia Idaho Illinois Indiana Iowa Kansas Kentucky Louisiana Maine Maryland Massachusetts Michigan Minnesota Mississippi Missouri Montana Nebraska Nevada New Hampshire New Jersey New Mexico New York North Carolina North Dakota Ohio Oklahoma Oregon Pennsylvania Rhode Island South Carolina South Dakota Tennessee Texas Utah Vermont Virginia Washington West Virginia Wisconsin Wyoming}

API_KEY = "YOUR KEY HERE"

@places = {}

States.each do |state|
  data = JSON.parse(Net::HTTP.get_response(URI.parse("http://maps.google.com/maps/geo?q=#{state}%20Ruby%20Street&output=json&key=#{API_KEY}")).body, {:symbolize_names => true})
  data[:Placemark].each do |place|
    address = place[:address]
    lon = place[:Point][:coordinates][0]
    lat = place[:Point][:coordinates][1]
    if address =~ /USA/ then
      @places[lon] = {:lat => lat, :lon => lon, :address => address}
    end
  end
end

@places_sorted = @places.sort
@farthest_west = @places_sorted.first
@farthest_east = @places_sorted.last

puts "Farthest west: #{@farthest_west}"
puts "Farthest east: #{@farthest_east}"

result = JSON.parse(Net::HTTP.get_response(URI.parse("http://maps.google.com/maps/api/directions/json?origin=#{@farthest_east[1][:lat]},#{@farthest_east[1][:lon]}&destination=#{@farthest_west[1][:lat]},#{@farthest_west[1][:lon]}&sensor=false&key=#{API_KEY}")).body)

pp result["routes"][0]["legs"][0]["distance"]["text"]