I've had my IPhone since October. I purchased it after getting rave reviews from my Mum & little bro who both have one & whilst I hate to say it, Mum was right. I love my IPhone.
I have an app to track time for my clients for billing purposes, track my menstrual cycle, do my netbanking, food/exercide diary, google maps, emails, ebay, notepad, calendar etc.
Before this I had a Nokia 6300 which was indestructable but I love my IPhone so much more. It just helps me run my life better.
It also allowed me to keep up to date much better during Cyclone Yasi which hit just south of me recently.
ETA - Mine costs me $60/month & includes 2GB data, free facebook, $500+ free calls & unlimited free texts.