Which is the best way to keep yourself organized
imp: GTD suggests using anything that can manage lots of lists quickly.  I'm currently using a Nokia N800 for managing my lists, and it works well.  There's a basic To Do app that's easy to use.  I'm upgrading to an N900 once it ships.  I had tried using a physical paper notepad, but it kept getting stale.  Lots of pages of half-crossed-out to-do items was annoying and not easy to sort through.