if you are using linux(ubuntu is a good choice). you must use gedit.
if you are using gedit. you must use 'todo' plugin.
but if you are ready for using this plugin maybe it doesn't work.
you must install ruby1.8+ and the python gtk lib.
$sudo apt-get install ruby
$sudo apt-get install python-gnome2-extras
link to the todo plugin: sourceforge.net/projects/gedit-todo
