gistfile1.rb

require 'singleton'

class PhoneLogger
  include Singleton

  def self.set_file(logfile)
    PhoneLogger.instance.set_file(logfile)
  end

  def set_file(logfile)
    @logfile = logfile
  end

  def self.log(message)
    PhoneLogger.instance.log(message)
  end

  def log(message)
    # some magic here
  end

end

PhoneLogger.set_file File.open(...)
PhoneLogger.log "hello world!"