PadNotes, an upcoming iPad app, offers a very simple, very useful function that the iPad seems to lack: You can type and draw on any PDF. Watch the video and you'll understand, the possibilities are quite impressive. [9to5Mac]
When will people learn, it's straight up ridiculous to have anything like this without a stylus...scratch that...a GOOD stylus.
You cannot write or draw with your fingertip, you, at some point need to rest your hand on the surface of the media. I've taken notes for 4 years using a Wacom enabled tablet/laptop, there is no substitute for the pen they make, it's very accurate, it's pressure sensitive, it has a built in eraser on the back of the pen, and it has a clicker on the side that enables right click.
The most you can do with the tip of your finger is make a quick, barely-legible note to pick up the dry cleaning, and play tic-tac-toe.