def url(style = self.default)
      path = self.path(style)
      host = self.host
      host = self.aliases[path.hash % self.aliases.count] unless self.aliases.empty?
      return "#{host}#{path}"
    end
def url(style = self.default)
      path = self.path(style)
      host = self.host
      host = self.aliases[path.hash % self.aliases.count] unless self.aliases.empty?
      return "#{host}#{path}"
    end
Acesss the URL for an attachment.

 Usage:

   @object.avatar.url
   @object.avatar.url(:small)
   @object.avatar.url(:large)