* added rails example to readme

README.markdown

@@ -2,7 +2,7 @@
 
 Provides a minimalistic web service to map IPs to countries from a local MySQL database generated from data available from maxmind.com. Uses Sinatra and MySQL. Inspired by this article: http://jcole.us/blog/archives/2007/11/24/on-efficiently-geo-referencing-ips-with-maxmind-geoip-and-mysql-gis/
 
-## Usage:
+## Installation:
 
 <pre>
 gem i bundler
@@ -22,6 +22,46 @@ curl http://localhost:9292/country_code_from_ip/[some ip here]
 
 Empty body and 404 response status means IP was not found in the database.
 
+## Use it
+
+A common use case might be detecting the user's language based on his location. In a Rails app you could setup a before_filter in your
+application controller like this:
+
+<pre>
+  ...
+  before_filter :set_locale
+  ...
+  def set_locale
+    if params[:locale]
+      I18n.locale = params[:locale]
+    else
+      res = geocode request.ip
+      if res.body.empty?
+        I18n.locale = Settings.default_locale
+        Rails.logger.warn "Geocoder found no match for #{request.ip}, falling back to default locale (#{Settings.default_locale})"
+      else
+        # implement a method to map countries to a language
+        I18n.locale = lang_from_country(res.body.downcase.to_sym)
+      end
+    end
+
+  # log the error, notify hoptoad, fallback to a default locale etc..  
+  rescue Timeout::Error => ex
+  rescue Errno::ECONNREFUSED => ex
+  end
+  ...
+  private
+  def geocode(ip)
+    url = URI.parse(Settings.geocoder.endpoint)
+    req = Net::HTTP::Get.new(url.path + ip)
+    Net::HTTP.new(url.host, url.port).start do |http|
+     http.read_timeout = Settings.geocoder.read_timeout
+     http.open_timeout = Settings.geocoder.open_timeout
+     http.request req
+    end
+  end  
+</pre>
+
 ## Why ?
 
 * fast