My affection is rooted in the device's versatility. You can do so much on such a small device it's amazing. Let me give you this morning as an example.
1) I woke up this morning using the alarm clock (I might have pushed the snooze once...)
2) Checked my email quickly (nothing super important)
3) I called Jessi to say good morning and wish her a good day at work.
4) I checked my work calendar to review when my meetings are today.
5) I looked up where I was having breakfast with some friends using the map.
6) While going to breakfast I listened to my audio book (a Walt Disney Biography).
7) I saw a sign I liked and took a picture of it (of a ninja school).
8) I then emailed that picture to Flickr and Facebook (which is also linked to Twitter) to share with friends.
9) Finally, I checked Twitter and Google Reader in Safari for any cool news.
This is just one morning and these are very diverse activities! I would even go so far as to say none of these were just plain goofing off - they all had a purpose that enriched my day. So yeah, the device looks cool, but the real attraction is all the different uses. Now if it can just replace my keys and credit cards (plus shave my face) I'll be set.