gistfile1.rb

class ApplicationController < ActionController::Base
  around_filter :you_are_here

  def you_are_here
    puts "***** NEW ACTION: #{controller_name} - #{action_name} *****"
    begin
      yield
    ensure
      puts "<pre>"
      if $! then
        puts "***** CAUGHT EXCEPTION: #{$!.message}"
        puts $!.backtrace
        raise
      else
        puts "***** CALL STACK *****"
        puts caller
      end
      puts "</pre>"
    end
  end
end