Don’t laugh. I used to think it was a weak replacement for Google Docs or Microsoft Word. But on the iPad, with the Pencil, I love how I can quickly read a doc & mark it up with a highlighter. Even if I add text, everything I highlighted or circled stays in place.
I like to take notes on people I talk to. Most phone book apps make it too hard. Cardhop allows one tap addition and even adds a time stamp, so I have context when I read notes like “going on vacation next week.”