For everyone subscribed to the philosophy of GTD, myself included, task managers are essential to managing the process digitally. Of course, they're only useful if you actually use them, as evidenced by the trail of task managers I've left in my wake as I search for one with the right combination of cross-platform access, easy task management, and a little bit of sharing functionality. It would also help if it were in a place I wouldn't forget about (or avoid) such as my web browser.