I wasn't an Iphone fan until I own one.
3rd party developers are a lot out there. The Iphone by itself isn't worth it. But after unlocked and jailbreak it, it's loaded with features that I can use (MS Word, Powerpoint viewer, exchange, IMAP, Financial tracking, VNS, touchpad mouse, remote iTune controller, games, SNES Simulators, etc.). Mostly it's because it's OSX based, therefore, there are a lot of support for it. I have yet to see the phone offers tons of those features.
So far, I really like it

I began to use my laptop less and less for my personal business but more with iphone. And to make it better, every data is synced automatically with my network at home. And this is on the slow EDGE network. :-p