Make sure you have all the artwork for your iTunes as they are what make cover flow so nice and collect you friends and contacts headshots for the contact list. Also I have been collecting wallpapers that I change every day.
So after half a day, I am LOVING my iPhone. All the stuff that led me to buy it is great. The stuff I wasn't so sure about is turning out to be not a very big deal. I'm getting more and more used to the keyboard. I finally figured out the correct settings for email (STOP...DOWNLOADING...EVERYTHING!!) However, there is one thing that I cannot believe they didn't have set up upon release:
Mass deletion of emails.
One at a time? And then I have to do it again to get it out of my trash? ARE YOU KIDDING ME? That's insane and there is no good reason for it. If you get a ton of emails a day, I can't even imagine the hassle.