diff --git a/README.md b/README.md
index ba0c5c6..9941761 100755
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-Betty (version 0.1.3)
+Betty (version 0.1.4)
 =====================
 
 Betty is a friendly English-like interface for your command line.
@@ -134,6 +134,15 @@ The following is a non-exhaustive list of things you can do:
     betty show me all processes by root containing grep
     betty show me all my processes containing netbio
     
+    Sizes
+    betty show size for myfile.txt
+    
+    Spotify
+    betty play spotify
+    betty pause spotify
+    betty next spotify
+    betty previous spotify
+    
     User
     betty whats my username
     betty whats my real name
diff --git a/lib/config.rb b/lib/config.rb
index e019bb0..b9af424 100644
--- a/lib/config.rb
+++ b/lib/config.rb
@@ -49,6 +49,28 @@ def self.interpret(command)
       }
     end
 
+    if command.match(/^(list\s(your\s)?voices)/i)
+      responses << {
+        :command => 'say -v "?"',
+        :explanation => 'List the availables voices for text-to-speech.'
+      }
+    end
+
+    if command.match(/^(?:set|change|make)\s+(?:your|betty\'?s?)\s+voice\s+to\s+(.+)$/i)
+      new_voice = $1.strip
+      responses << {
+        :call_before => lambda { self.set("voice", new_voice) },
+        :say => "OK. My new voice is #{ new_voice } from now on."
+      }
+    end
+
+    if command.match(/^what\'?s?(?:\s+is)?\s+your\s+voice\??$/i)
+      my_voice = self.get("voice")
+      responses << {
+        :say => "My voice is setted as #{ my_voice }."
+      }
+    end
+
     if command.match(/^(?:set|change|make)\s+(?:your|betty\'?s?)\s+name\s+to\s+(.+)$/i) || command.match(/^stop\s+speak(ing)?\s+to\s+me$/)
       new_name = $1.strip
       responses << {
diff --git a/lib/internet.rb b/lib/internet.rb
index 9072d1a..6e693ec 100755
--- a/lib/internet.rb
+++ b/lib/internet.rb
@@ -39,8 +39,8 @@ def self.compress(command)
       what_file = match[1].strip
 
       {
-        :command => "cd #{what_file}; tar -czvf #{what_file}.tar.gz *"
-        :explanation => "Compress the contents of #{what_file} directory, outputting the compressed file to parent directory"
+        :command => "cd #{ what_file }; tar -czvf #{ what_file }.tar.gz *",
+        :explanation => "Compress the contents of #{ what_file } directory, outputting the compressed file to parent directory"
       }
     end
   end
diff --git a/lib/sizes.rb b/lib/sizes.rb
new file mode 100644
index 0000000..d181754
--- /dev/null
+++ b/lib/sizes.rb
@@ -0,0 +1,61 @@
+module Sizes
+  GIGA_SIZE = 1073741824.0
+  MEGA_SIZE = 1048576.0
+  KILO_SIZE = 1024.0
+  @command_string = ""
+  
+  # Return the file size with a readable style.
+  def Sizes.readable_file_size(size, precision)
+    case
+      when size == 1 
+      	return "1 B"
+      when size < KILO_SIZE 
+      	return "%d B" % size
+      when size < MEGA_SIZE 
+      	return "%.#{precision}f KB" % (size / KILO_SIZE)
+      when size < GIGA_SIZE 
+      	return "%.#{precision}f MB" % (size / MEGA_SIZE)
+      else 
+	return "%.#{precision}f GB" % (size / GIGA_SIZE)
+    end
+  end
+  
+  def self.show_sizes(where)
+    #puts "your command: #{@command_string}"
+  	pipe = IO.popen("du -s #{ where } | sort -n")
+	while (line = pipe.gets)
+	  match = line.match(/^(\d+)\s+.+?$/)
+	  if match
+	    puts "#{ Sizes.readable_file_size(match[1].to_i, 2) }    #{ line }"
+	  else
+	    puts line
+	  end
+	end
+  end
+
+  def self.size_stuff(command)
+    @command_string = command
+    match = command.match(/^show\s+(?:size|disk|usage)\s+for\s+(.+?)$/i) || command.match(/^what[^\s]*\s+(?:the|)\s*(?:size|space)\s+(?:for|in|of)\s+(.+?)$/i)
+    
+    if match
+      where = match[1].strip
+      is_this_directory = where == '.' || where.downcase.match(/^(this\s+)?(?:dir(?:ectory)|folder|path)?$/)
+      
+      {
+        :call => lambda {self.show_sizes(is_this_directory ? '.' : where )},
+        :explanation => "Shows the size of files in #{ is_this_directory ? 'all the files in the current directory, including subdirectories' : where }."
+      }
+    end
+  end
+  
+  def self.interpret(command)
+    responses = []
+    
+    sizes_command = self.size_stuff(command)
+    responses << sizes_command if sizes_command
+    
+    responses
+  end
+end
+
+$executors << Sizes
diff --git a/lib/spotify.rb b/lib/spotify.rb
new file mode 100755
index 0000000..b2600c7
--- /dev/null
+++ b/lib/spotify.rb
@@ -0,0 +1,75 @@
+module Spotify
+  
+  def self.start(command)
+    matching = command.match(/^(start|resume|play)\s+(spotify|((?:the|my)\s+)?music)$/i)
+
+    if matching
+      {
+        :command => "osascript -e 'tell application \"spotify\" to play'",
+        :explanation => "Starts playing spotify."
+      }
+    else
+      nil
+    end
+  end
+
+  def self.pause(command)
+    matching = command.match(/^pause\s+(spotify|((?:the|my)\s+)?music)$/i)
+
+    if matching
+      {
+        :command => "osascript -e 'tell application \"spotify\" to pause'",
+        :explanation => "Pauses spotify."
+      }
+    else
+      nil
+    end
+  end
+
+  def self.next(command)
+    matching = command.match(/^(next|advance)\s+(song|music|track|spotify)$/i)
+
+    if matching
+      {
+        :command => "osascript -e 'tell application \"spotify\" to next track'",
+        :explanation => "Makes spotify play the next track."
+      }
+    else
+      nil
+    end
+  end
+
+  def self.prev(command)
+    matching = command.match(/^prev(?:ious)?\s+(song|music|track|spotify)$/i)
+
+    if matching
+      {
+        :command => "osascript -e 'tell application \"spotify\" to previous track'",
+        :explanation => "Makes spotify play the previous track."
+      }
+    else
+      nil
+    end
+  end
+
+
+  def self.interpret(command)
+    responses = []
+
+    start_command = self.start(command)
+    responses << start_command if start_command
+
+    pause_command = self.pause(command)
+    responses << pause_command if pause_command
+
+    next_command = self.next(command)
+    responses << next_command if next_command
+
+    prev_command = self.prev(command)
+    responses << prev_command if prev_command
+
+    responses
+  end
+end
+
+$executors << Spotify
diff --git a/lib/user.rb b/lib/user.rb
index 3d34836..17c8a6d 100755
--- a/lib/user.rb
+++ b/lib/user.rb
@@ -48,6 +48,8 @@ def self.interpret(command)
     
       command_to_use = ""
       case program
+      when "go"
+        command_to_use = "go version"
       when "mysql"
         command_to_use = "mysql -u root -p -e ' SELECT VERSION(); '"
       else
diff --git a/main.rb b/main.rb
index b84e47f..9a702be 100755
--- a/main.rb
+++ b/main.rb
@@ -1,8 +1,11 @@
 #!/usr/bin/env ruby
+require 'logger'
 
 $URL = 'https://github.com/pickhardt/betty'
-$VERSION = '0.1.3'
+$VERSION = '0.1.4'
 $executors = []
+$LOG = Logger.new(File.open(ENV['HOME'] + '/.betty_history', 'a+'))
+
 Dir[File.dirname(__FILE__) + '/lib/*.rb'].each {|file| require file }
 
 BettyConfig.initialize
@@ -42,6 +45,9 @@ def interpret(command)
   $executors.each do |executor|
     executors_responses = executor.interpret(command)
     responses = responses.concat(executors_responses)
+    if executors_responses.length == 1 and executors_responses[0][:command] 
+      $LOG.info('main_interpret') {"#{command} ==> #{executor.name} ==> #{executors_responses[0][:command]}"}
+    end
   end
   responses
 end
@@ -71,7 +77,9 @@ def run(response)
 
 def speak(text)
   if User.has_command?('say')
-    system("say \"#{ text }\"") # formerly mpg123 -q
+    say = 'say'
+    say += " -v '#{BettyConfig.get("voice")}'" if BettyConfig.get("voice")
+    system("#{say} \"#{ text }\"") # formerly mpg123 -q
   else
     has_afplay = User.has_command?('afplay')
     has_mpg123 = User.has_command?('mpg123')