use icons for service links

app/helpers/accounts_helper.rb

@@ -1,22 +1,31 @@
 module AccountsHelper
   def link_to_service name, service
-    case service.name
-    when 'twitter'
-      link_to name, 'http://twitter.com/' + service.key
-    when 'friendfeed'
-      link_to name, 'http://friendfeed.com/' + service.key
-    when 'mixi'
-      link_to name, 'http://mixi.jp/show_friend.pl?id=' + service.key
-    when 'github'
-      link_to name, 'http://github.com/' + service.key
-    when 'facebook'
-      if service.key =~ /^\sd+$/
-        link_to name, 'http://www.facebook.com/profile.php?id=' + service.key
-      else
-        link_to name, 'http://www.facebook.com/' + service.key
-      end
-    when 'iddy'
-      link_to name, 'http://iddy.jp/profile/' + service.key
-    end
+
+    base_uri = case service.name
+               when 'twitter'
+                 'http://twitter.com/'
+               when 'friendfeed'
+                 'http://friendfeed.com/'
+               when 'mixi'
+                 'http://mixi.jp/show_friend.pl?id='
+               when 'github'
+                 'http://github.com/'
+               when 'facebook'
+                 if service.key =~ /^\sd+$/
+                   'http://www.facebook.com/profile.php?id='
+                 else
+                   'http://www.facebook.com/'
+                 end
+               when 'iddy'
+                 'http://iddy.jp/profile/'
+               end
+
+    text = if %w(mixi twitter friendfeed github facebook).include? service.name
+             image_tag("/images/#{service.name}_32.png")
+           else
+             name
+           end
+
+    link_to text, base_uri + service.key
   end
 end