How to setup and use GeoKit with Rails 2.3.2

Install the GeoKit gem and the Rails plugin: ```ruby sudo gem install geokit script/plugin install git://github.com/andre/geokit-rails.git ``` Edit config/environment.rb: ```ruby Rails::Initializer.run do |config| config.gem "geokit" end ``` Generate a model and migration file with script/generate model Place: ```ruby class CreatePlaces < ActiveRecord::Migration def self.up create_table :places do |t| t.string :name t.string :external_id t.string :external_type t.decimal :latitude, :precision => 15, :scale => 10 t.decimal :longitude, :precision => 15, :scale => 10 t.timestamps end add_index :places, :latitude add_index :places, :longitude add_index :places, [:latitude, :longitude] end def self.down drop_table :places end end ``` Configure GeoKit: ```ruby class Place < ActiveRecord::Base acts_as_mappable :default_units => :kms, :default_formula => :sphere, :distance_field_name => :distance, :lat_column_name => :latitude, :lng_column_name => :longitude end ``` Use your GeoKit enabled model: ```ruby Place.find_within(105, :origin => Place.last) ```