Windows: GeeTeeDee is a lightweight tool for wrangling your GTD to-do lists that sports drag-and-drop task sorting, customisable groups and more.
GeeTeeDee is a lightweight task management application modelled after the GTD workflow. You can easily create new tasks, attach a due date and notes and easily drag and drop them between your custom lists. The interface for GeeTeeDee is minimalist and easy to navigate, and you can easily switch between a compact and expanded view and use the Cleanup button to fresh lists and archive completed tasks.
Our biggest complaint about GeeTeeDee isn't anything about the interface or workflow; it's about portability. This lightweight application begs to be portable but isn't. We were unable to find any settings within the application or the accompanying files to toggle portability on either. We hope the upcoming Mac OS X and mobile versions will herald in the arrival of a portable version too. GeeTeeDee is freeware, Windows only.