This is one of my favorite task managers. You can enter the tasks by date and time, give priority to each task by assigning colors and best of all, you can manage your tasks from anywhere – your phone (there is a version each for android, ipad & blackberry phones) or your computer.
You can manage your tasks offline, integrate them with Google Calendar. Sharing of tasks is easy and so is getting reminders – by Email, by Instant Messenger or by SMS
In short, it is the best way to manage tasks – Never Forget the Milk or anything else again !