Graphical Notes!
Yes, this means that you can draw a graphical note for every task. You can do this with your finger, or if your phone has one: with a stylus. Just long-press the task for which you want to draw the note, and then, in the menu that appears, press 'Graphical note'. You can use this feature in any number of situations; for example, a friend sets a date at that new restaurant, but you've never been there before, so you ask him/her to draw directions for you:
Audio Notes!
You can even record audio notes just like you would draw graphical ones. Just press 'Audio note' in the task's menu (or press F when the desired task is selected) and you can play or record a note for each task.

You don't have to worry about your phone's storage space when you delete the task because the PNG image file in the application folder and the audio file on the SD card will be deleted as well.
Written Notes!
Many people have asked for written notes with their tasks, so this is now available in the menu, or by pressing W when the desired task is selected.