I keep getting amazed by how much is included in iOS devices (or, I'm sure, many other similar devices). For example I only noticed today that my iPhone 4 includes a dictaphone ("Voice Notes"). It's better quality than the Olympus digital one I paid good money for a few years ago, it's easier to use, has way higher capacity, and it can email voice notes to myself so I have them on my mac too (or to others of course).
I mean, this is seriously useful stuff, but in amongst everything that this little device can do, it's just thrown in as a extra you may not even notice. Jeepers.