Tasks can be created with a due date, notes, tags, links to URLs, and files and links to people from your address book. You can also make your tasks recurring.
Just divide your tasks by contexts. Where should they be done? At home? At the office? On your laptop? Whenever you can access the Internet?
Some of your tasks are related to your life projects. If you're a student, divide your school tasks by subjects. If you're a developer, organize your tasks and ideas by your software projects. You can also treat projects as categories for your tasks.
As GTD says, you are supposed to review your plans and tasks on a daily and weekly basis. Use the process/review inspector. Just press the @ key when browsing through your tasks or use any 'Process...' or 'Review...' button.
Navigate through your tasks, contexts and projects using only the keyboard. Most functions in the interface can be done with keyboard shortcuts.
Thanks to the beta release of the Quicksilver plugin you can throw your text thoughts and files to the iGTD inbox. More features coming soon!
Using more than one Mac? Sync iGTD with .Mac so that changes on one show up on all. Use iSync to copy your calendar and tasks to iCal, your iPod, your Palm, or other handheld.
In the preferences panel, turn on the menu bar item of iGTD. You will be able to add a new task to the given context or project. You can also open any browser or file link quickly. Or even make iGTD synchronize your tasks with your mobile device.