From DGT GTD
There are five phases in the GTD workflow: Collect, Process, Organize, Review & Do.
The "Inbox" is part of the collecting process in the GTD method, it is where all incoming notes, projects, meetings, events, or anything else one wants to get out of their head goes, in order to later be processed.
As soon as you set one of the following attribute the task disappears from the Inbox:
- due date
David Allen public Podcasts: http://www.davidco.com/webinarsalacarte
Getting started podcast: http://www.davidco.com/audio/DavidAllen-GettingStarted.mp3