Ive already reviewed two of the major productivity systems out there on this blog: Simpleologyand Mark Fosters Do It Tomorrow.Today, Leo Babautas productivity system, Zen to Done, is up for review. Zen to Done (ZTD) is based on David Allens Getting Things Done (GTD), as well as on the work of Stephen Covey and others. Its a set of 10 habits that will help you get organized, simplify your life, get things under control, and get things done. Instead of trying to implement all 10 habits at once, Le